Arche uses her telescope and views the top of the mausoleum of Nazarick's Tomb from a distance, but cannot identify what era or setting it originates from. Hekkeran believes that will just mean more rewards for later. Roberdyck, however, notes there could be a chance that a powerful undead could lurk within, but Imina wonders aloud what kind of person could have built a tomb in this exact area to have been buried within. Hekkeran is excited at finding more from the unknown, but Arche is too focused on the reward money to care about wonder; her teammates laugh at her single-mindedness, with Hekkeran acknowledging this could be their best job ever.
In the dead of night, Hekkeran finalizes the plan that they will have each team move simultaneously at a given signal. Gringham's team enter their entry point, and find a burial room with an unknown banner over a sarcophagus, with none able to identify the crest. Alone, Gringham and his party, Heavy Masher, talk casually for a moment. Upon examining the banner, they find it is woven with precious metals worth tens of coins for the one banner. Gringham orders them to leave it to focus on the main objective, and they open the sarcophagus. They are astonished to find it filled with brim treasure, and when meeting with Hekkeran in the central mausoleum, the other teams had already found an incredible treasure as well.
When arriving at the stair to descend into the First Floor, the smell of the dead fills the air, leading to worry of undead below, which Parpatra requests his team look for hidden entries around the surface. Parpatra only asks for a compensation fee of 10% to all treasures should a safe route be found, with Hekkeran and Grigham agreeing, but before Erya can voice in his opinion, Parpatra takes his leave. As they enter, Roberdyck senses no undead responses, and Heavy Masher members note the tomb to be at least 600 years old; making it more valuable and a historical find. Erya being impatient hurries the others as he wants to kill monsters, and everyone sees general skeletons running at them from down the hallway ahead. Gringham eliminates the skeletons and advises them to be cautious going forward as there could be a more powerful undead later on.
At the base camp, Momon notes that the workers have entered the tomb, and another gold adventurer states they are still comrades in this mission, hoping they'll return safely; he then asks Momon's opinion. He slips stating they'll die, but quickly correct himself that they have that kind of resolve in case they run into danger to keep a safe mindset as a new ruin means unforeseen dangers; the gold adventurer buys into that and is relieved of any confusion. Momon goes to rest as the gold adventurer takes first watch, and returning to his tent, he returns to his Ainz persona to let Pandora's Actor take his place while he oversees the eventual retaliation for the Worker's invasion into the tomb.
Ainz enters the Throne Room to an awaiting Albedo. Asking Albedo about the preparations for the planned visit of the Workers, Albedo assures him that preparations are complete, that their "guests" will enjoy the surprises. Ainz is pleased and looks forward to seeing Albedo's measure of hospitality. As he sits on the Throne, Albedo pulls up Light Monitors to view the various Worker groups; Ainz notes their entry, ordering Albedo not to let a single one go unscathed. As Albedo promises to punish the thieves for trespassing into Nazarick, she asks Ainz which group he'd like to use as guinea pigs for his 'new sword', with the Overlord thinking about it. A little while later, as Team Foresight is walking with Arche noting it was all too easy to reach as far as they did, Imina warns them to be quiet. Looking around the corner, they see a group of undead soldiers. Arche detects 1st Tier Skeleton mages providing them support, which could prove problematic for them going forward. So, Roberdyck uses his Holy Faith Magic to destroy the undead group in an instant.
Meanwhile, outside, Parpatra's Dragon Hunt notes the loss of profit, but their leader notes entering an Unknown Tomb right away invites too much danger and is using the others as the Canaries in a Coal Mine. Yuri Alpha surprises them by acknowledging a level headed decision. Dragon Hunt turns as they see the Pleiades (minus Narberal) at the top of the staircase; one of Dragon Hunt members notes that maids at a tomb is bad taste, which triggers the Pleiades' rage. Green Leaf tenses up sensing this killing intent, except for the guy who triggered them; when calling for to kill them, Yuri calms her sisters to focus as they will kill them, but due to their restrictions by Ainz, they cannot kill them directly. Yuri summons the Old Guarders to be Dragon Hunt's opponents. Parpatra believes that the Old Guarders are the most powerful of the tomb; with the Pleiades looking at each other. Parpatra finds that his group are now the Canaries. Yuri calls for their battle to begin.
After a few minutes, The Pleiades are saddened to see such weaklings fighting a small squad of Old Guarders, as only Parpatra and another member of Dragon Hunt are all that remain. Giving a narration, the Pleiades see all but Parpatra dies. As Entoma drools overeating one of the fallen Dragon Hunt members, Yuri reminds her that they are only to collect the fallen. After Parpatra falls, Yuri calls for the still breathing to be healed and sent to the torture chamber, while the dead are examined by Ainz.
In the Tomb, Heavy Masher runs from a squad of Elder Liches shooting fireballs at them. As they run, the thief of the group finds a door to enter thru and hide. Feeling safe, a teleportation trap spell is triggered. Finding themselves in a dark room, they soon meet Kyouhukou, who after his introduction is asked who is he and finds the repetition annoying. Gringham offers a trade to escape him, but Kyouhukou is thankful for their presence as his children need food, and are tired of roach on roach cannibalism. As the roaches eat him alive, another of his men was transported to Neuronist Painkill, a Special Intelligence Collector, who elaborates that the Worker groups have entered Nazarick, the most Honorable place in the world. Neuronist goes on about Ainz, her love of him, and going on a tangent about how much she hates Albedo and Shalltear. As Neuronist's creator suffered from Kidney Stones, she feels that she should start with a special tool inspired by it.
Somewhere in the tomb, one of Erya's elven slaves hears something up ahead, and they soon meet with Hamsuke; who is sparring with the Lizardmen and a Death Knight. When asking his slaves what kind of magical creature she is, they have never seen it before, and Erya is enraged at their ineptitude. Hamsuke informs Erya that they are to fight to see the results of Hamsuke's training, with the Lizardmen & Death Knight will not intervene on their fight. As both take stances, Hamsuke introduces herself, but Erya doesn't feel a need to seeing her as inferior; thus Hamsuke will erase this loser with no name.
As she charges, Erya evades using martial arts but is attacked by a headbutt from Hamsuke before getting an attack in. Erya's nose bleeds from the damage, and he loses any sense of composure; Hamsuke however, sees him using his abilities and remembering her training to keeps a distance until she knows more about them. So to know more, Hamsuke switches to close combat standing upright, enraging Erya to attack wildly, but Hamsuke's natural fur and claws are strong enough to shield from his sword. Changing attacks to her tail, Erya is critically injured and berates his elf slaves to heal and enchant him; reluctantly complying, they buff their master in his blood lust.
Hamsuke politely requests they all attack to see the outcome, but Erya attacks like a madman with Hamsuke countering by cutting off both of his arms using Martial Arts Slashing Strike. Erya roars at his slaves to heal him, but with seeing him suffer and about to die, they all laugh at his plight. Erya, realizing he's all alone, is given a mercy killing by Hamsuke by a tail strike to his face, caving in his skull. Turning around for critique, Zaryusu acknowledges Hamsuke's activated martial arts capabilities when using Slashing Strike to remove Erya's arms. Looking back, they all see the elves kicking Erya's corpse; confused by the sight of it, believing it is how they mourn.
Elsewhere, Team Foresight realizes they were teleported by way of a magical trap. Seeing a dark hallway, they realize by an understanding of the Imperial Colosseum, that they are to fight someone. Looking ahead, past the caged doorway, they are to enter some sort of arena. Hekkeran also realizes this, and after moving forward entering the center of the Colosseum, they believe they are outside when seeing a starry night sky. Arche opts to use her Fly spell, but they are all startled by the surprise arrival of a Dark Elf with a microphone, introducing Foresight to an empty crowd. They are then introduced to Ainz as their opponent.
The episode contains examples of:
- Asshole Victim: None of the Elves mourn for their master, instead they laugh at his pain followed by kicking at his corpse.
- Berserk Button: The Pleiades are not too pleased that their attire are ridiculed, especially it meant bad about their masters' opinions.
- Entertainingly Wrong: Dragon Hunt assumes that that the Pleiades are the strongest beings in the Great Tomb of Nazarick by judging their "worried" looks. However, the women aren't worried; They were just thinking how stupid the team's logic is.
- Mercy Kill: Hamsuke does this to Erya to end his suffering.
- The Stinger: Foresight finds themselves at the Amphitheater where Ainz is waiting.
- Took a Level in Badass: Thanks to Ainz and the Lizardmen's training, Hamsuke can go toe to toe with high-level Adventurers.
- Zerg Rush: Kyouhuko has his cockroach children devour Gringham and another Heavy Masher member.
- The Workers enter the Great Tomb of Nazarick.
- Dragon Hunt, Heavy Masher and Tenmu are slaughtered by Nazarick's defenses.