Cate, May, and Shaw are trapped in Hollow Earth.
Tropes:
- Age Cut: When Young Shaw is sent to the Gilded Cage where his old self was first introduced, the camera settles on him and a Body Wipe cuts to his older self in the same position on the lead-up to G-Day in 2014.
- Angry Collar Grab: Lee angrily grabs Hiroshi's suit collar in a desperate effort to get him to shut up and listen to him the moment that Hiroshi calls his lost parents' Monarch crusade "madness that devoured my childhood".
- Apologetic Attacker: Young Shaw, upon getting free, apologizes to Young Emiko a second in advance of restraining her and taking her hostage.
- Armor-Piercing Question: Bill struggles to answer when his young son asks him just before Operation Hourglass where his uncle Lee is going.
- Armor-Piercing Response: When Kentaro confronts Hiroshi, the latter asks him what he means when saying it's too late to talk to Cate, prompting Kentaro to deliver the bombshell: "Cate died."
- Bleak Abyss Retirement Home: The retirement home where Shaw was locked up for 33 years already came across as a Gilded Cage in its first appearance, but in Young Shaw's ending detailing his transition to Old Shaw, the place appears even more miserable when he's forcibly sent there by his own nephew as a broken shell of a man; spending the next 33 years sitting in front of a TV and taking meds which dope him up until the onset of G-Day.
- Body Wipe: The Age Cut on Young Shaw when his series-spanning story officially ends.
- The Cameo: Dr. Suzuki reappears in a minor role among the audience witnessing Operation Hourglass's launch.
- Continuity Nod:
- General Puckett begrudgingly cuts off Monarch's funding and warns Bill Randa not to let his obsession with proving the Hollow Earth exists consume him. Eleven years later, Randa's done exactly that—orchestrating the Skull Island expedition to definitively prove his theory and regain the government's support—and loses his life in the process.
- General Puckett's retort that they have no way to get aggressive Titans to listen to reason is a subtle nod towards the ORCA from Godzilla: King of the Monsters, which was used to communicate with the Titans and pacify them if they become aggressive.
- Connected All Along: It's revealed that Kentaro's mother Emiko Randa (née Matsumoto) once worked for Monarch's Japanese branch as a nurse, and fell in love with Hiroshi Randa after he rescued her when she was taken hostage by Lee Shaw.
- Cry into Chest: Emiko cries into Kentaro's chest when she sees him in hospital.
- The Cuckoolander Was Right: In the 80s, Shaw tells Hiroshi that Bill — who Hiro and the rest of Monarch have dismissed as mad — was completely right about the Hollow Earth, and he says that humans and Titans are meant to coexist in balance. Hiro refuses to believe this at the time, and instead he dismisses his uncle Lee as mad like he assumes his parents were.
- Death Seeker: Kentaro briefly admits to wanting to follow his lost friends to the grave while he's reeling with grief.
- Death Wail: Hiroshi lets out a heart-rending wail when the news from Kentaro that Cate is dead and he's indirectly at fault for it sinks in — for all that Hiroshi's spent the series being a terrible father, a crap husband, and an equally bad nephew in this episode, the anguished sound out of him is all but guaranteed to make you cringe in pain.
- Diving Save: Shaw runs to May just in time to push her out of the way of a deadly lightning-bolt that was building on top of her.
- Dramatic Irony: It's 1962, and Puckett humorously says in a speech to his fellow officers that they're at least another decade away from putting a man on the moon; "Two [decades] if we do it right".
- Due to the Dead: Operation Hourglass buries Ben when he dies on arrival.
- Dynamic Entry: The very first sign of Keiko's presence in the final scene in an arrow firing into the Brambleboar's eye when it's menacing Cate.
- Emerging from the Shadows: The Brambleboar is first introduced lurking in the shadows, only visible by some of its facial features and the fog of its breath, before it stalks out towards Cate. Likewise, Cate's savior is introduced completely silhouetted, before she steps closer and the light on her face reveals her to be Keiko.
- Facepalm: Lee in the 80s rubs his eyes in pain when forcing himself to recount his memories of what happened the first time that he slipped into the Hollow Earth.
- Faint in Shock: Young Shaw after escaping the Axis Mundi is so shocked by the reveal of his time dilation, and by seeing an adult man claiming to be his Hiro presenting the very same pocket knife which Shaw knows he gave him before his trip, that he passes out.
- Foreshadowing: While the grainy display on the Titan monitor that Bill Randa and Dr. Hiroshi are using isn't very high resolution, the shark-shaped head of the Ion Dragon can be seen emerging from the portal on the screen, foreshadowing its attack on Shaw's team and reappearance in the final episode.
- Held Gaze: Hiroshi and Lee when they meet again in 1982.
- Helmets Are Hardly Heroic: Played With. Shaw and the other three background characters in Operation Hourglass never wear their helmets outside of the actual passage into Hollow Earth, removing them as soon as they've landed.
- Hope Spot: After sniffing a terrified Cate, the Brambleboar—a pig-like Planimal with More Teeth than the Osmond Family—trots off... and just as she starts to relax it comes back and tries to eat her.
- I'm Not Hungry: Young Shaw in the flashbacks rejects the food that he's provided while held captive in quarantine without any idea of why he's being treated like this.
- Internal Reveal: Kentaro tells Hiroshi at the episode's climax that the reason he encountered the group in Algeria was because they were looking for him, something he'd never even considered.
- I Will Find You: Shaw promises May that they will find Cate after being separated from her in the Hollow Earth.
- Kick the Dog: When Lee defends Bill as having been right all along, Hiroshi, who in the 80s has spent years dismissing his late father as crazy, emotionally seizes up, and the way he dismisses Lee before the latter is locked away in a gilded cage is outright cruel. He responds to his honorary uncle all but begging him not to leave things like this by blaming him, Bill and Keiko for the Titans re-emerging, coldly leaves the pocket knife which Lee gifted him twenty years ago and which he kept for all these years behind on Lee's desk, and when Lee angrily affirms that the 50s trio's actions were not madness, Hiro responds to Lee's face that it being a choice instead probably makes it worse.
- Lecture as Exposition: Puckett provides a detailed exposition about Operation Hourglass when he's explaining it to his fellow military officers in attendance.
- Little "No": A time-displaced Lee mumbles one when an adult Hiroshi shows him the pocket knife that Lee gave him in 1962, confirming that he's the same person.
- Mass "Oh, Crap!": Everyone in attendance at Operation Hourglass reacts with justified alarm, and then begins running for cover, when the project goes wrong and generates a giant suction vortex of doom.
- Meaningful Name: It certainly wasn't intentional In-Universe, but Operation Hourglass's name becomes something of foreshadowing after the unexpected end result of the project is time displacement which causes the sole survivor to skip by years' worth of time on Earth.
- My God, What Have I Done?: Hiroshi exclaims in Japanese "What have I done?" when the realization that his daughter is (supposedly) dead and it's partly his fault sinks in.
- No Good Deed Goes Unpunished: Emiko, who's working as a nurse in the past, sneaks a cookie in for the hunger-striking Lee out of simple kindness, and Lee seizes the opportunity to sneak-attack her and take her hostage so that he can force answers out of his host. Lee himself is briefly apologetic to her about it. Then again, not only is Emiko completely understanding of what drove Lee to such desperate measures after the incident and holds no hard feelings, but this incident is the catalyst for her and Hiroshi catching each-other's eye, leading to their marriage and her son's eventual birth. On the other hand, since this was Hiroshi, it might have been more of a double subversion for her in the long run barring Kentaro's birth...
- Nothing Is the Same Anymore: Emiko admits while comforting her grieving son that he's correct to feel that after experiencing the apparent loss of the half-sister he'd only just grown close to and all their other friends, nothing can ever be the same for him again.
- Offscreen Teleportation: Lee slipping out of bed when Emiko's back is turned for a moment.
- Oh, Crap!:
- May freaks out the moment it hits her that Cate followed her back into the power plant and has fallen into the Axis Mundi with her and Lee.
- When Cate wakes up in Axis Mundi she finds herself face-to-snout with a Brambleboar, leaving her cringing in terror as it sniffs her.
- Outliving One's Offspring: Hiroshi collapses in grief when he believes that Cate is dead.
- Pet the Dog:
- Puckett is genuinely torn up by Shaw's apparent death even though he had to drop the hammer of cutting off Monarch's funding, apologizing to Bill Randa for not having acted to stop things from going too far. He also pleads with Bill to not let his obsession with Monarch cause Hiroshi to lose his stepfather.
- Verdugo, who has spent the rest of the series being acidic and cold to just about everyone she holds a conversation with, is genuinely sorrowful when informing Kentaro that his half-sister and their friends are all apparently dead, and she even put in the time to wait by his bedside for him to wake up so she could tell him herself despite the temporal demands of her job.
- Please, Don't Leave Me: In 1982, Lee all but begs Hiroshi to work together with him to work things out instead of letting Monarch cart Lee off to isolation in the retirement home indefinitely.
- Rage Breaking Point: Kentaro has a short one when he and Emiko get home from the hospital. Emiko acts like a mother hen over his broken leg, and within seconds, Kentaro, holding in a lot of grief over his friends' apparent deaths including that of the long-lost sister he'd only just warmed up to, sharply loses his temper and snaps at her in one word to stop.
- Reluctant Retiree: Bitter and angry over being told his late father—who had neglected him—was right all along, Hiroshi Randa has Lee Shaw sent to a retirement home for Monarch employees despite Shaw physically not being much older than he is, where he spends the next thirty-three years plotting to escape.
- Rescue Romance: After returning to Earth from the Axis Mundi, Lee Shaw takes his nurse Emiko Matsumoto hostage in an attempt to force the higher-ups to bring him Bill Randa. After getting Shaw to let her go, Hiroshi later apologizes to Emiko and gives her a bouquet of flowers, and she gives him some advice on how to handle Shaw. The two would later get married, with Emiko giving birth to Kentaro Randa.
- Say My Name:
- Shaw when he breaks free in the Monarch hospital with a hostage in hand and demands to be taken to his friend."BILL! RANDA! Get me BILL! RANDA!!!"
- Both Lee and May are screaming Cate's name, hoping she'll hear, when searching for her in the Axis Mundi.
- Shaw when he breaks free in the Monarch hospital with a hostage in hand and demands to be taken to his friend.
- Ship Tease: Upon being told by Shaw that Cate fell into the Axis Mundi with them, May is far more concerned about finding Cate and making sure that she's safe than she is with her own safety.
- Single Tear: Lee sheds a tear when recounting the deaths of the remaining Operation Hourglass personnel in the Axis Mundi.
- Survivor's Guilt: Kentaro assumes that Cate and May died when they fell into the portal, and laments to his mother that he should have died with them; later lashing out at Hiroshi and blaming him for his half-sister's apparent death.
- They Died Because of You: An angry Kentaro tells Hiroshi flat that it's his fault Cate supposedly died, as if he hadn't been the kind of father that he was whose negligence set the series' plot in motion, then Cate wouldn't have been in the Kazakhstan power plant when it collapsed.
- This Cannot Be!: When Kentaro angrily tells him that Cate died while they were searching for him, Hiroshi is shocked and accuses Kentaro of lying to get back at him for having hurt him. As Kentaro glares at him, Hiroshi begs his son to tell him it isn't true, then breaks down in horror and grief. Kentaro shows his father no sympathy, furiously shouting that if Hiroshi hadn't selfishly disappeared then Cate would still be alive.
- Thousand-Yard Stare: Young Shaw has an utterly terrifying gaze that looks like it's looking a little too far at everything, when he emerges in the Japanese forest after his week-long entrapment in Axis Mundi which saw him as the sole survivor. When he's in the Monarch retirement home the last time that we ever see Young Shaw, he's sitting in front of the TV but he's staring past it into nothing.
- Too Dumb to Live: Subverted during Operation Hourglass. The disturbed Vile Vortex's violent suction appears to magnetically target metal objects and equipment foremost, yet Dr. Suzuki and another observer choose a wholly-metal trailer to take cover inside. They're just lucky that the Vortex didn't pick that trailer up before the disturbance stopped.
- Tragic Keepsake: Before his first Hollow Earth expedition, Shaw left his pocket knife with Hiroshi. When he returns twenty years later, Hiroshi uses the knife to prove his identity when Shaw takes a nurse hostage and demands they bring him Bill Randa, who has since died.
- Vertigo Effect: The background behind Young Lee moves farther away a la Jaws when a suddenly-adult Hiroshi shows him the pocket knife that Lee gave his single-digit aged honorary nephew just before Operation Hourglass.
- Waking Up Elsewhere:
- In the 2015 storyline, Kentaro wakes up in hospital with Tim and Verdugo at his bedside after the events of the previous episode. Likewise, May and Cate wake up in an unfamiliar forest with an outright alien sky and atmospheric weather after they entered the Vile Vortex in the last episode.
- In the backstory storyline, Lee Shaw wakes up inside a quarantine tent after escaping from Hollow Earth. It gets even worse when he discovers while forcing his way out from the tent that twenty years have passed on Earth while he was caught in a space-time dilation in the Hollow Earth.
- Weird Weather: As an effect of the portal closing behind them, Shaw and May have to dodge electrical discharges that build up as multicolored lightning on the ground before reaching critical mass and bursting into the sky. One of these lightning bursts killed a member of Shaw's team when he first arrived.
- Wham Shot: Cate is saved by Keiko Randa, who seemingly hasn't aged a day since she was dragged off by the Endoswarmers.
- What Is Going On?: A nurse asks this when Lee breaks free in the hospital.
- What the Hell, Hero?:
- When Bill Randa angrily suggests summoning another Titan to give the government a new "enemy" to feel threatened by, General Puckett sternly retorts that even if Randa could do that, there's no guarantee the Titan would be as passive as Godzilla and could turn out to be actively malicious and impossible to stop.
- When reuniting with his father, Kentaro calls him out for his Secret Other Family, having disappeared without sending word that he was OK, and that his secrecy seemingly caused Cate's death.
- Worth It: Old Shaw flippantly comments to May after recounting his backstory that if he can get May back home from the Axis Mundi before decades of time have passed her by up top like they did for him, then he'll consider his tragic first visit to the Axis Mundi and the consequences it had on his life to be worth it.
- Year Outside, Hour Inside: Shaw went into a Hollow Earth portal in the 1960s, then came out in the 1980s with virtually no time having passed for him. More extreme still, Keiko is still alive down there and hasn't visibly aged, despite an even longer period having passed above ground.
