Full title: "Third Singularity - Sealed Ends of the Four Seas: Okeanos [Voyager of the Storm]". Written by Yuichiro Higashide.
With the repairing of the third Singularity, Chaldea has learned the existence of beings known as the "Demon Pillars," eldritch creatures that in legends, served as familiars to a certain ancient king. Besides that, the Protagonist and Mash Kyrielight are then tasked with fixing the fourth Singularity, an endless Atlantic ocean in 1573.
Rayshifting straight onto a pirate ship, and beating its crew, the cast soon heads to Pirate Island, where they soon meet/defeat the pirate captain Francis Drake, and with her help, must set sail in a treasure-hunting quest to find the Holy Grail, battling evil pirates and the legendary Argonauts along the way.
Prelude
In 1573 AD, Sir Francis Drake and her crew, helming the ship Golden Hind, are chased through stormy seas by an enemy ship manned by an unknown Servant. Taking extreme evasive manoeuvres, Drake's crew manage to escape a massive whirlpool to evade their pursuer.
In Chaldea, the Protagonist has a dream of a memory of Mash Kyrielight (known then as "Number 2"), from her time in Chaldea before the Grand Order began (her "5110th awakening"), tended to in her daily routine by Dr. Romani Archaman.
Woken by Fou, the protagonist joins Mash in the Command Room to be briefed by Dr. Roman and Da Vinci. They deduce that the presence of Flauros in the previous Singularity, a supposed Demon God, implies the possible involvement of the ancient king of Israel - King Solomon; the 72 Demon Gods were originally his familiars. Roman is skeptical and suspicious, believing the Demon Gods to not truly exist, and Flauros to be an imposter assuming the name.
The team is tasked with solving the Third Singularity - in 1573 AD. Curiously, the Singularity is simply broadly located in "the ocean", its geography shifting with the Singularity, such that there is no one specific area the Singularity is located around. The sea within the Singularity only possesses several scattered islands, with the Rayshift aiming to place the team (including Fou, with Roman allowing him to go) on one of them.
With nothing but a rubber floaty given by Da Vinci for emergencies, the protagonist, Mash and Fou Rayshift into the Third Singularity.
Pirates of Chaldea
The team Rayshift into the Singularity successfully... materialising onto the top deck of a pirate ship, completely surrounded by its confused and aggressive crew. After a brief fight, Mash pacifies the crew and interrogates them. They learn that the pirates are just as unaware of their surroundings, claiming they suddenly appeared in unfamiliar waters, their compasses and maps rendered useless.
They further learn that the pirates are heading for a rumoured "Pirate Island" for to replenish supplies and to meet with fellow pirates. Mash commandeers the vessel and orders them to continue their course for Pirate Island.
Pioneering Pirate Queen
Arriving at Pirate Island, the crew set ashore, subduing a band of overenthusiastic pirates who impulsively attack. The lead pirate offers to lead the crew to his boss, and takes them inland to their supposed secret hideout. The pirate claims his boss to be the Great Pirate, Sir Francis Drake, the pioneer of the Age of Exploration who circumnavigated the world; Mash suspects Drake to be a living person, and a key individual native to the current era. She explains Drake's history to the protagonist, which is overheard by the pirates.
Reaching the hideout, the heavily drunk Drake allows the team into the camp. The lead pirate, Bombe, praises the group to Drake, having mistaken Mash's exposition for idolisation of Drake. For their part, the Chaldeans, including Roman, are astonished to find that Drake is, in fact, a woman, before attempting to explain the Singularity to the Captain. Drake reveals she is aware the ocean is now abnormal, but in her drunkenness, challenges Chaldea to best her before letting them speak further.
After a duel, Mash and the protagonist manage to best Drake, who displays an unexpectedly high amount of power despite her supposed status as a living person. Dr. Roman notices that Drake is emitting a magical energy reading, while the placated Drake offers to hear them out. Revealing that she also doesn't know their exact location in the sea, Drake officially surrenders to the team, offering to serve under them as part of their crew.
As the sun sets, the revelries for the crew's new leadership continue. Drake explains that the sea has suddenly become abnormal, becoming an amalgamation of different climates, with no continents aside from small islands seeming to exist. Drake further reveals that she has encountered Servants, and she and her crew were intending to set out on another journey the day after Chaldea's sudden arrival.
Drake suddenly holds a toast with what appears to be the Holy Grail itself, the source of her immense power, astonishing Chaldea (aside from the drunken protagonist). From recounts by her crew and herself, Drake had apparently recovered the Holy Grail earlier after discovering the city of Atlantis in a whirlpool guarded by Poseidon, who attempted to unleash a new flood to destroy the world. Drake managed to defeat Poseidon and sink Atlantis into the whirlpool, while seizing the Grail as loot, unintentionally saving the world long before Chaldea's arrival.
As night falls, after quelling a sudden fight amongst the drunken crew, Chaldea explains the situation to Drake. Drake willingly hands over her Grail as a reward, but the Singularity remains unchanged. Roman deduces that the Grail she holds is the real Holy Grail of the era that Drake rightfully obtained, and distinct from the Grail deliberately placed by Lev to create the Singularity. The two Grails in competition with each other is what created the turbulent seas, and retrieving Lev's Grail is the only way to resolve the Singularity.
Da Vinci and Dr. Roman convince Drake to ally with Chaldea with the aim of returning her seas to normal. Da Vinci deduces that Drake has no wish for the Grail herself, and unconsciously used its power to simply provide enough food, drink and safety for her crew. Roman hypothesises that a potential reward of "treasure" exists due to the dreams of pioneers and pirates embedding itself within the Singularity and made manifest by the Grail, as further encouragement for Drake. Drake eventually agrees, holding yet another round of drinks, to Mash's dismay.
Ghost Ship and New Island
With Drake on their side, the crew set out for the seas the next day on the Golden Hind, Drake's ship. They defeat a ship of ethereal "pirates", which Dr. Roman hypothesises to be spiritual bodies representing the "concept" of the average pirate from the Age of Exploration, which will spawn spontaneously in the seas until the Singularity is resolved.
The Hind reaches a nearby island, where Servants are detected. Mash, the protagonist and Drake make landfall to investigate while the rest of the crew remain behind on the Hind. Drake detects a presence and instinctively fires a shot before moving further inland to investigate. There, they find a stone tablet speaking of a "Bloodaxe King", the title of a Viking king who ruled Norway in the 9th Century, before being ambushed by more ethereal pirates serving a "King Eric". After fending them off, they try to leave the island's forest, noting the Servant's presence has yet to move.
As they leave, Drake makes a hearty wager with Mash and the protagonist to find treasure (asking that they accompany her on a worldwide voyage should she win), asking what they desire should they win. When they explain to her that they have no wish to be granted should they win, Drake notes that having no wish is paradoxically the hardest wish for her to grant as a merchant, as she cannot deliver what they do not want. Before they can discuss her odd philosophy further, they are attacked by the enemy Servant - a Berserker, the Viking king Eric Bloodaxe, who seems completely insane.
They fight and defeat Eric, who seemingly disappears. Searching the island for treasure, Drake discovers Eric's Viking ship moored on the shore. Looting the ship, Drake finds the ship's logbook (counting it as treasure to win their wager), and learns of an island 10 hours to the northwest, which they set course for.
Lightning and Goddess
Meanwhile, within a large stone labyrinth, a lone young purple-haired Servant encounters a monster stalking the maze.
The Hind sails for the northwest island, Drake and Roman noting the sudden but subtle change in the environment despite the relatively short journey. They encounter and defeat an attacking enemy pirate ship. Drake doesn't recognise its Jolly Roger flag, and Roman is tasked with analysing it as they approach the island.
The crew arrive at the much larger northwest island, detecting a Leyline to use further inland, curiously surrounded by Dragon-Tooth Warriors. Clearing out the skeletal enemies, they set up the summoning circle, Da Vinci giving a history lesson on spice trade in the Age of Exploration to pass the time (astonishing Drake with a modern pepper shaker). Roman discovers the owner of the Jolly Roger from earlier, but the communications to Chaldea mysteriously cut out before he can reveal their identity, and an earthquake briefly shakes the island.
Returning to the ship, they find the ship locked in place as if by an anchor. Mash and the protagonist suspect a Bounded Field has been placed preventing the ship from moving. Once again leaving the crew behind, they set out to track down and defeat the source of the Bounded Field, discovering several empty fortresses. Finding an open mountain cave, they enter to find an enormous stone labyrinth, which an emboldened Drake gleefully dives into.
Fighting their way through skeletons and monsters, and traversing the labyrinth purely on Drake's whims (Mash quietly recording their path), Mash proposes holding hands as to not get lost, much to the protagonist's embarrassment. Drake suddenly smells blood nearby, and the party immediately set out to follow the trail, defeating the monsters near its end. Meanwhile, the purple-haired Servant and the monster Servant observe the party from nearby. The monster Servant decides to attack them, however, the purple-haired Servant chooses not to help him.
The party is attacked by the Berserker Servant, Asterios, the Minotaur of Greek Mythology - the Labyrinth itself being his territory. After an intense fight, they manage to defeat and gravely injure Asterios, after which the purple-haired Servant, the goddess and Gorgon sister Euryale, reveals herself and surrenders to prevent Drake from finishing him off. Euryale mistakenly believes the party to be allied with another enemy Servant from whom she had ran from, while the party mistakenly believed her to be in danger from Asterios.
After clearing up their misunderstandings, Euryale explains that Asterios had put up the Bounded Field not to trap them, but to prevent their enemies from getting in. Deciding their only option is to either have Asterios die, or to remove the Field, the pair decide to remove the Field and ally with Drake, who welcomes them both with open arms.
Blackbeard's Misery
Out to sea, aboard the ship of the enemy Servant hunting Euryale, a perverted pirate captain Servant, his two crewmembers and fellow Servants, famed female pirate duo Anne Bonny and Mary Read, openly lament their employment under their depraved captain. The captain voices his intent to take Euryale and Drake's Holy Grail, sensing their presence. He calls for his crew to ready themselves - Mary, Anne, the still living Eric, and another Servant wielding a spear, a hero of the Trojan War.
At the shore of the northwest island, Asterios lowers the Bounded Field, freeing the Golden Hind, and the party sets sail with their two new allies, following Eric's map and defeating more rogue pirates. While singing a song for the crew as Asterios heals from his injuries, Euryale explains her predicament - she is being hunted by a depraved Pirate Servant after her solely for her cute looks.
The Hind is suddenly pursued by the enemy Servant's ship, flying the Jolly Roger from before - at the same time Dr. Roman finally reconnects to the team, and reveals the captain's identity as none other than Edward Teach, or the infamous pirate captain, Blackbeard. Drake recognises Blackbeard's ship as the one who had chased her before, and flies into a rage.
The heroes meet Blackbeard for the first time, who nearly overwhelms them with his disgustingly perverted nature alone, making sexually harassing comments towards nearly every female on board the Hind. Blackbeard sends the returned Eric Bloodaxe to retrieve Euryale. As the two ships battle, the Hind is completely unable to damage Blackbeard's ship.
Eric boards the Hind to take Euryale, and the injured Asterios rushes to protect her. Based on the turbulence that hid Eric after their first battle, Roman hypothesises that Eric is a Servant summoned by Blackbeard, further deducing from this that Blackbeard possibly holds the Holy Grail. The rest of the heroes intercept Eric to protect the injured Asterios, and kill the Bloodaxe King for good.
Mash suddenly saves the protagonist from a sneak attack by Blackbeard's spearman Servant, who attempted to end the battle early by attacking the Master. Drake decides to retreat, shooting out the ropes between their ships and preparing to flee. Impressed by Drake's skill, Anne Bonny decides to intervene, and shoots at the Hind's bilge, causing an explosion and the ship to begin sinking. Drake volunteers to patch the hole herself, but Asterios suddenly leaps below to lift up the ship himself despite his injuries. Dropping barrel bombs behind them, they manage to escape Blackbeard, with Drake swearing vengeance.
Hunter of the Three Stars
Making landfall at the next island, the crew find Asterios still alive, but once again gravely injured, his wounds reopened from the battle. The damages to the Hind mean the ship is now grounded, forcing the crew to make repairs. Euryale suggests sourcing materials from the island's native magical monsters.
As the party of Servants (and Drake) hunt, Drake discusses how to defeat Blackbeard's seemingly invincible ship, the Queen Anne's Revenge. While recounting Blackbeard's history, Dr. Roman suspects his Noble Phantasm to be the Queen Anne's Revenge, and deduces its power to be dependant on the strength of its crewmembers - the defeat of Eric Bloodaxe having weakened the ship enough for the Hind to successfully escape.
They suspect his search for Euryale is so she can bolster his strength further (as well as fulfil his lusts). After slaying a pack of wyverns, the party decide to repair and strengthen the Golden Hind using processed dragon scales as materials, setting out to find a nest to slay the 30 wyverns required for such a task.
Meanwhile, a Rogue Archer Servant and her small teddy-bear-like "Darling" are cooking elsewhere on the island, and detect the party's presence. They decide to find them, needing information as to why they were summoned. However, the bear accidentally angers the archer with comments on a lack of cute girls on other islands, resulting in him being accidentally thrown by her through the forest into a pack of wyverns.
The party arrive and save the small, talking (and perverted) bear, whom they believe to be a familiar, from the wyverns. The still-angered archer arrives soon after, believing the bear, apparently her lover, to have cheated on her. The party quickly clears things up and explains the situation to the two. The archer and bear reveal themselves to be the Greek goddess Artemis and her lover Orion, respectively, to the astonishment of all present, including fellow Greek Servants Euryale and Asterios.
Artemis explains that after she learnt that Orion was to be summoned, she had lowered her Divinity to be summoned instead as a Heroic Spirit to take Orion's place, forcing him into the form of a small plush-like bear. The two join the dragon hunt, and help lead the party to a dragon nest, where they slay an angered dragon, a parent of the wyverns they had fought, finally giving them enough scales to complete repairs.
Queen Anne's Revenge
Repairs on the Golden Hind are completed, with a new ram created with the leftover scales, and Asterios, once again healed, ungrounds the ship. They set sail for their rematch with Blackbeard in unknown waters, now joined by Artemis and Orion. Planning to ram Blackbeard's ship with the Hind, Artemis suggests boarding their ship herself to cause a riot as a distraction for the approach, using Orion's power to walk on water as the son of Poseidon.
On the Queen Anne's Revenge, Blackbeard's Trojan Servant spots the Hind's approach, and they prepare for battle. Euryale takes a shot at Blackbeard, which misses. She continues taking shots at Blackbeard's crew, charming those she hits into starting riots (and being personally killed by Blackbeard out of jealousy). Artemis boards, posing as Orion, and engages Blackbeard's crew while Orion himself sneaks into the reserve ammo hold. Mary engages Artemis, but both she and Orion signal Drake as an explosion rips open the Revenge's ammo hold - sabotaged by Orion - leaving it open to be rammed by the Golden Hind.
With the Revenge all but completely neutralised, Drake and the crew board for the final battle.
Desperate Battle
Mash and the heroes engage and defeat Anne Bonny and Mary Read, who fight together as a single Servant. They send encouragement to Blackbeard as they disappear, and the crew head for the final showdown with Blackbeard. Drake and Blackbeard confront each other, and in an intense battle, Blackbeard is defeated and fatally wounded.
Drake admits she is honestly impressed by Blackbeard as an opponent, and Blackbeard drops his guard. Suddenly, he is betrayed and stabbed by his own spearman Servant, astonishing Drake. Revealed to be the Trojan hero, Hektor, he admits he is impressed - he had been waiting for Blackbeard, who possessed the Holy Grail, to drop his guard, but the pirate's perverted nature had hidden a genuinely clever mind, and was wary 24/7. Blackbeard takes a shot at the traitor, but misses, and Hektor takes the Grail from him.
Hektor reveals the plan was to hand the Grail to an idiot, and let him cause the era to fall apart, only to be foiled by Drake's appearance. Hektor boards the Hind, revealing his true objective to be Euryale. He attempts to take her, but is held off by Asterios. Fending off Hector in battle, Asterios is injured, but Blackbeard makes one final shot at Hektor, who manages to flee with Euryale on his own ship. Artemis wishes to pursue him, but Orion stops her, pointing out that as the greatest Trojan hero and a Lancer, he is most powerful against them, particularly as Artemis is depowered and not in her true body.
With the Grail gone, Blackbeard's subordinates vanish, with Blackbeard himself disappearing with a final reference-filled farewell, with newfound respect for Drake (who immediately rejects and condemns him).
Tracks Down the Dandies
Elsewhere, Hektor's true masters, supposedly named the Argonautai, await his arrival on another ship, their arrogant blonde-haired captain planning to offer up Euryale to gain even greater power. With the support of his lover and second-in-command, a young purple-haired witch Servant, the captain plans to retrieve an object named the "Ark" after Hektor's arrival, to make himself the king of Okeanos with it and the Holy Grail.
The Golden Hind continues to pursue Hektor's smaller ship past more rogue pirates to rescue Euryale. They discuss Hektor, the power of his spear Durandal, and his plans for Euryale, noting that Euryale is not that powerful of a Servant to warrant capture without a specific goal in mind. As Drake resolves to rescue her and rouses her crew, Mash notes how Drake's personality and good nature reminds her of the protagonist, but is unable to reconcile her good nature with her brazen actions like that of a villainous outlaw in history.
A storm rolls in, and Drake orders the crew to go at full sail in spite of it, the new dragon scale hull allowing the ship to handle the stress with ease. They fight their way through a sudden ambush by a ghost ship before the storm winds down.
On Hektor's ship, Hektor explains to Euryale that his Master requires a Divine Spirit for their plan - offering a god as a sacrifice to the world in order to destroy it. However, before Euryale can determine his Master's identity, they spot the Golden Hind approaching, having caught up.
As the heroes close in, Asterios flies into a rage, and rushes to rescue Euryale after Orion unsuccessfully attempts to calm him down, with the rest of the heroes following him. Boarding Hektor's ship, they battle their way through his crew to reach Hektor himself. Hektor attempts to land a sneak attack on Asterios by distracting him with Euryale, but is prevented by Mash.
Mash, the protagonist and Hektor fight, and Hektor is forced back, surprised by Mash's toughness. However, with the fight dragging on for too long, another unfamiliar ship approaches - helmed by Hektor's superiors. With his ride here, Hektor decides to get serious.
World's Oldest Pirate Ship
The Hind is unable to damage the enemy ship, whose captain sends out his greatest weapon - the Greek hero and Berserker Heracles, who launches boulders at the crew, barely blocked by Asterios. Hektor takes the opportunity to flee while the enemy captain taunts the heroes as evildoers trying to "correct" the world.
Artemis recognises the enemy ship as the famed Argo, the Greek ship of the group of adventurers, the Argonauts, led by the great hero and arrogant captain - Jason, Hektor's true master. Jason resolves to crush the Golden Hind here and now, with Heracles leading the attack. Jason offers to call off Heracles if they hand over Euryale, to which they refuse.
Jason sends his second-in-command and lover, the young Princess Medea or Medea Lily, the Witch of Colchis, to attack the crew. To the disgust of Orion and Artemis, their relationship is noted to be remarkably toxic, with Jason making references to her vengeful and murderous adulthood, to which Medea Lily claims apparent unawareness of. Medea Lily joins the fight with Heracles, sending her Dragon Tooth Warriors to assault the crew.
As the battle rages on, Medea Lily decides to board and fight the crew herself personally. With her combat prowess somewhat lacking, they manage to hold her off. However, Medea Lily joins forces with Heracles to fight the crew again. Asterios resolves to fight Heracles, hoping to atone for the deaths he has caused as a monster.
They manage to defeat Heracles, only for Jason to reveal Heracles' true power - immortality in the form of the Noble Phantasm God Hand, granting Heracles twelve lives to represent the Twelve Labors. With no way to beat Heracles, the crew are forced to retreat to the Hind while Jason celebrates his victory. Hektor hands Jason the Grail, who openly gloats that he only requires Euryale and "the Ark" to complete his plans.
Suddenly, Heracles specifically attacks Euryale with intent to kill, surprising Jason, who requires her alive. Asterios defends her, and holds off Heracles alone. Vowing to return to being human to atone for his sins in life and for Euryale, who was the first being to remember his true name, he manages to push back Heracles with his resolve, but soon loses the upper hand. Medea Lily is sent to retrieve Euryale, but is kept back by Drake.
With both his allies on the frontline occupied, the frustrated Jason grants permission for Hektor to unleash his Noble Phantasm - Durindana Pilum - and throws his spear at Asterios. However, Asterios grabs Heracles at the last moment so they are both fatally impaled together, delaying the enemy Berserker and allowing the crew to escape. In his last moments, Asterios thanks the protagonist for also using his true name, entrusts them with protecting Euryale, and professes his love for her. Euryale calls for Asterios to not regret becoming a monster, to which he replies that a monster must still receive punishment, before throwing himself, Heracles, and Hektor's spear into the ocean to sink, buying them time with his sacrifice.
Medea Lily assures Jason that she can track the heroes' Magical Circuits wherever they go despite the delay, and with Drake's skill as a pioneer, she will easily find the Ark they seek and lead the Argonauts straight to it. Privately speaking with Hektor, it is revealed that he and Medea Lily have ulterior, more destructive motives for Euryale, and decide to withhold the truth from Jason to let him remain in blissful ignorance. They decide to warn Heracles upon his return, noting that he maintained enough intelligence to realise Euryale's true role in their plan, which led him to try and kill her instead to prevent worldly destruction.
Lost Ark of the Covenant
The Hind successfully escapes the Argonauts, mourning Asterios' loss. They decide to steal the Ark the Argonauts seek, with Roman deducing it to be the Ark of the Covenant, the relic holding the Ten Commandments that Moses received from God. Roman voices confusion as to the Argonauts' intent with the Ark, as attempting to use or open it would only incur divine punishment, resulting in mass destruction.
With no leads, no strategy to defeat Heracles another ten times, and another ghost ship to defeat, they set sail to search for the Ark, with Roman scanning nearby islands for magical energy signatures. Orion and Mash note the strangely young appearance of Medea and her alliance with Jason, believing she should've been summoned in her adult form as a Servant, after her betrayal, which should make her and Jason completely incompatible.
Roman hypothesises that she has been summoned in her younger form, before she married Jason, but Euryale notes that she should still have all her lives' memories as a Heroic Spirit - before realising the implication that Medea is simply pretending to be oblivious to her fate is far more horrifying than the alternative.
After many duds, Orion is suddenly shot by an arrow from the next island carrying a letter from the two Archer Servants seeking their help from the Argonauts, one of whom Artemis recognises. They (including Artemis) make landfall, and head out to personally meet the two Servants - Atalante, the hunter in service of Artemis (who recalls their last meeting with Chaldea in the France Singularity, and is rather mortified by Artemis' true appearance), and David, the King of ancient Israel, holder of the Noble Phantasm, the Ark of the Covenant, and the first Servant summoned to the Singularity.
Defeat Heracles
David explains the Ark's nature: all who touch it will die, and it cannot be returned to spirit form - should David perish, the physical Ark will remain as long as someone possesses it. Atalante was summoned as part of the Argonauts, but upon learning Jason's plans for the Ark, she betrayed them, sought out David herself, revealed Jason's intentions for the Ark, and went into hiding with David to await help from other Servants.
Jason believes sacrificing Euryale to the Ark will make him king of the seas - however, David reveals that doing so would in fact destroy the entire era. Sacrificing a Divine Spirit to the Ark, an object that brings death to all who touch it, would cause the Ark to lose control and cause mass destruction, which in the unstable reality of a Singularity, would destroy the world completely without needing to wait for its natural collapse or using a Grail. They suspect Jason does not know the true result of his plan, and an outside party may have convinced him to do so under false pretenses.
Formulating a strategy against the Argonauts (barring Jason, who Atalante assures them will not fight directly), they decide their best approach is to lure Heracles, their most dangerous foe, away and force him to touch the Ark, destroying him completely, with the protagonist proposing their own risky idea to bait him personally.
Betting It All
The Argonauts arrive at the heroes' island under Medea Lily's direction, detecting Euryale's presence. Before Jason can order her retrieval, however, they are attacked by a large volley of arrows from the island - aimed directly at Jason himself, forcing them to defend.
As part of the plan, the Archer Servants on the island all fire their Noble Phantasms at Jason at the same time - Atalante's Phoebus Catastrophe, Artemis' Tri-Star Amore Mio, Euryale's Eye of the Euryale, and David's Hamesh Avanim. Medea Lily and Hektor are forced to protect Jason, and Heracles is sent out alone to deal with the Archers - exactly as the heroes have planned.
The protagonist and Euryale, following Roman's directions, act as live bait for Heracles, luring him further inland as he pursues them. Mash and the other Servants help force Heracles back three times whenever he catches up to allow the pair to gain distance, before they finally reach the underground catacombs further inland - where the Ark lies. The two leap over the Ark to escape Heracles, who halts as he realises their true intentions.
With Heracles cornered and right in front of the Ark, the Servants engage in one last battle with the Berserker, and manage to force Heracles to touch the Ark, completely destroying him. With their greatest foe defeated, the heroes gather for the final battle aboard the Argo.
Pioneer of the Stars
The Golden Hind pursues the Argo for the final confrontation, catching up with Drake's superior skill. Cornered, Jason uses the Grail to summon waves of Shadow Servants in desperation. Fighting through the Shadow Servants, the heroes board the Argo, and Jason sends Hektor to confront them while Medea Lily protects Jason. In a climactic battle, Hektor is defeated for good, but attempts a final parting blow to make Euryale touch the Ark. However, anticipating it, Euryale neutralises him completely with Eye of the Euryale, as revenge for Asterios, and Hektor disappears.
David confronts Jason, asking to know who gave him his plan to begin with. It is revealed that Jason was completely unaware his plan would lead to global destruction, and was told by an unknown benefactor, another "king", that his plan would merely give him infinite power, which he would've used to form a utopia where he is respected as an ideal king. Medea Lily admits her betrayal, and that Jason's dream is an impossible one due to his twisted nature. She has pledged to protect Jason for the sake of the "king" who had chosen him, and tells him their "plan" is technically true on the merit that global destruction would make Jason the most powerful by default.
Medea Lily decides to continue "protecting" Jason as she has promised - and forcibly takes the Holy Grail from him. Using its power, she transforms Jason into the 30th of Solomon's 72 Demon Gods - Sea Fiend Forneus, the second Demon God Pillar encountered by Chaldea. Drake is undeterred, and leads the heroes in the final Grand Battle for the Singularity against Forneus and Medea Lily.
The heroes eventually prevail, returning the dying Jason to normal. Medea Lily admits her memories as Princess Medea are returning, and apologizes for being unable to protect her love, who was quick to betray everything as it was the only way he knew how to live. Jason disappears, cursing Medea Lily. Before she disappears soon after, the protagonist demands to know her true allegiances. She refuses to admit her master's identity, but reveals that she had lost to him as a mage, implying their true foe is also a powerful mage. She implores Chaldea to prepare and to gather "stars" to light the sky and stand against the "beast within man's heart", before disappearing, leaving behind the Singularity's Holy Grail.
With the Grail retrieved, the Singularity is resolved and the era is corrected. Slowly, the team's allies begin to disappear, including Drake's crew, who happily thank Mash and the protagonist for the voyage. Orion voices his hopes to meet Chaldea again in another form, while Euryale voices her own to meet Asterios again, before giving the protagonist a goodbye kiss. Atalante admits she is glad she wasn't defeated this time around, but wonders how she will continue to worship Artemis as she vanishes.
Mash asks David for advice regarding the Demon Gods, as he is the father of King Solomon, but David admits he knows nothing of summoning, much to Dr. Roman's disappointment. David is curious as to Dr. Roman's apparent knowledge of Demon Gods, but Da Vinci passes him off as a massive fan of King Solomon, explaining his skepticism towards the Demon God Pillars. David passes off Solomon as a cruel good-for-nothing, and entirely capable of being the mastermind behind humanity's destruction, before disappearing.
Finally, the heroes thank Captain Drake for her help, briefly regretful that she will lose all memories of the Singularity upon its resolution. Mash regrets she was unable to find a wish before the end to tell Drake, but Drake assures her that she already has a wish - all humans have a wish, just that some may go without learning it. She assures Mash that she is better off not learning her wish, but is certain she will realise what it is by the end. Drake accepts her fate in history and thanks the heroes for showing her the vastness of the world, asking that they remember the fun they had together, before they return to Chaldea.
Back in Chaldea, they celebrate their third victory, and Dr. Roman promises to look into the new Demon God and investigate King Solomon's era of 1000 BC using Chaldeas and Sheba, despite their accuracy decreasing in the BC era. As they return to their rooms to rest, Mash confides in the protagonist what she has learnt - that good and evil people alike all contribute to history, and humanity is brutal in its pursuit to gain power and achieve their desires. However, it is that trait that gives humanity the power to achieve the impossible, and makes them human, a power that Mash wishes to know and gain on her journey.
Tropes:
- Accidental Hero: As Mash puts it, Poseidon and Atlantis were probably the most significant threats in the Singularity, but Drake, none the wiser to this, blundered onto the island, beat up the guy in charge and stole his treasure. Just doing what she would've been doing anyway, she happened to save the world.
- Alcohol-Induced Idiocy: Both the protagonist and Drake get completely wasted at one point. Downplayed as neither does anything particularly idiotic while in this state, merely acting silly.
- Already Done for You: Drake and crew obtained the Holy Grail before Chaldea ever showed up. Apparently it was originally in Poseidon's hands and somehow a perfectly normal pirate managed to defeat a Divine Spirit and sink Atlantis. This was presumably the actual "main plot" of the Singularity, but Drake's crew saw it as just another treasure raid.
- Blood Knight: Francis Drake herself enjoys a good fight now and again.
- Butt-Monkey: Orion basically exists to be abused. Also, no one takes Blackbeard seriously.
- Broken Pedestal: Atalante was mortified when she learned that the Goddess she worshiped, Artemis, was a lovestruck airhead.
- Debut Queue: Medea Lily becomes available to summon after this story's completion.
- Evil Laugh: As the chapter opens, we're greeted with... Blackbeard laughing maniacally. And then using "lol" in place of said laughing.
- Final Boss: A Dual Boss against Medea Lily and Jason, who has been forcibly transformed into the Demon God Forneus.
- Foreshadowing:
- The very beginning of chapter recapitulates The Reveal in Septem, that Lev was actually Flauros, one demon among 72. Medea Lily's final words only make it more obvious that the Big Bad is Solomon. The heroes try to ask his father David for information, but he can only offer cryptic hints.
- In the above conversation about Lev, Roman argues that this "Demon God" fits the "modern" idea of demons too well to be one of Solomon's actual familiars, indicating that this may be an impostor claiming Solomon's name. The conclusion is correct: the Big Bad is a fake Solomon. The argument, though, is bunk, possibly intentional misdirection—the reason Roman knows this is a fake Solomon is because he's the real one.
- Heel–Face Turn: Atalante was previously an enemy Servant in Orleans, but she is an ally here. Likewise, she also used to be a member of Jason's Argonauts, but left after knowing his true goal and teamed up with David.
- Heroic Sacrifice: Asterios sacrifices himself to take one of Heracles's lives and to protect Euryale.
- Infinite Supplies: Drake has been using her Holy Grail to keep her crew well-fed and safe in the high seas.
- The Juggernaut: Absolutely nothing stops Heracles and his charge... until he touched the Ark of the Covenant, that is...
- Marathon Boss: Dear god, Heracles. Almost literally, even, given that you're running the hell away from him the whole time.
- Metaphorically True: Jason's benefactor told him that sacrificing a god to the Ark of the Covenant would grant him power and immortality. When King David, the keeper of the Ark hears this, he declares it obviously false, sacrificing Euryale would disrupt the already-unstable Singularity and cause it to collapse. Jason asked Medea Lily if this was true and her response was that if the singularity collapsed, all his enemies would be dead, making him all powerful. And since he too would be dead, he'd be incapable of dying further.
- Obfuscating Stupidity: It is said that if Hektor gave his all about strategy and combat, Jason's side could have won. Except that Hektor doesn't like Jason, so he sabotaged his chance of victory by following Jason's inept commands to the tee. Likewise, Blackbeard, to the point that he looks more like a Butt-Monkey with others noting that if he's serious, he could've achieved more.
- Offscreen Moment of Awesome: How did Drake ever manage to beat Poseidon? Keep in mind this was how she got the Grail to begin with, so she apparently did this without any special powers.
- "The Reason You Suck" Speech: When Jason's plans crumble, Medea Lily delivers a devastating verbal takedown of him as to why his plans were doomed to failure from the start.
