Cotter Martin jumps the turnstile at the Polo Grounds and slips into the 1951 playoff baseball game undetected.

Bobby Thomson hits a famous home run and Cotter Martin wrestles the ball away from the cheering crowd.

Manx Martin sneaks into his son's bedroom while Cotter sleeps and steals the prized baseball.

Nick Shay drives across the desert and reunites with artist Klara Sax at her installation of repainted Cold War planes.

Nick reluctantly admits to coworkers at a baseball game that he owns Bobby Thomson's famous home-run ball.

Nick surprises Marian with a hot-air balloon ride over the desert as her birthday present.

Matt Shay watches a home video of the Texas Highway Killer committing a murder on repeat.

Brian Glassic visits memorabilia collector Marvin Lundy and is shown the prized Bobby Thomson baseball.

Nick travels to New Jersey and pays Marvin Lundy thirty-four thousand dollars for the Bobby Thomson baseball.

Nick attends a waste-management conference, has an affair with Donna, and confesses to her that he once shot a man.

A teenage Nick Shay is convicted of negligent homicide and sent to a juvenile detention facility.

Manx Martin sells Cotter's stolen baseball to Charles Wainwright and his son outside Yankee Stadium.

Nick accidentally shoots and kills George the Waiter with a sawed-off shotgun that George insisted was not loaded.

Nick confronts Brian Glassic during a trip to Kazakhstan and strikes him over the affair with Marian.

Nick returns home from Kazakhstan and reconciles with Marian, and the two grow closer than they have ever been.

Pool 1 follows the central spine of Underworld, beginning with Cotter Martin's legendary catch of Bobby Thomson's home-run ball at the 1951 playoff game. Manx Martin steals the ball from his son, setting it on a decades-long journey that eventually reaches collector Marvin Lundy and then waste executive Nick Shay. Nick's story moves between his present-day life in the early 1990s — where he reunites with old flame Klara Sax in the desert — and his troubled past as a teenage criminal in the Bronx. The pivotal tragedy of his youth, the accidental shooting of George the Waiter, shapes everything that follows, landing Nick in prison before he rebuilds his life as a successful professional. By the epilogue, Nick confronts his friend Brian about an affair with Marian, and the two finally achieve a fragile, hard-won peace together.

The baseball's journey and Nick Shay's life from crime to redemption.

An FBI agent interrupts J. Edgar Hoover at the baseball game to report that the Soviet Union has detonated a nuclear bomb.

Cotter returns home after the game and quietly tells his sister Rosie about the baseball, trusting her to keep the secret.

Nick and Marian lie in bed at night, speaking without truly connecting, each retreating into private thoughts.

Marian Shay runs into Nick's colleague Brian Glassic at a classic-car show and the two share a flirtatious lunch.

Brian Glassic visits the Fresh Kills landfill on Staten Island after leaving Marvin Lundy and feels his faith in humanity revived.

Marvin Lundy walks through his old New York neighborhood, reflects on his late wife Eleanor, and argues bitterly with a stranger on the street.

Nick and his brother Matt eat dinner with their mother and quietly debate whether their father was killed or simply abandoned the family.

Matt Shay visits his old chess mentor Bronzini and they discuss how drastically the neighborhood has changed since his youth.

Marian meets Brian at her assistant's house and shocks him by smoking heroin, daring him to join her.

Nick and Big Sims argue about race and institutional trust at a jazz club until the tension spills into a headbutt fight outside.

Klara Sax and her friend Esther search the Bronx for the graffiti artist Moonman 157 but find only a burned-out block.

Ismael Munoz leads his crew of young artists to an abandoned subway station and paints an entire train carriage overnight.

Matt and Janet go camping near the missile range and Matt realizes at sunrise that he has been facing the wrong direction all night.

Marian calls Nick and proposes marriage over the phone while anti-war protesters take over radio broadcasts outside her family home.

Sister Edgar removes her rubber gloves and embraces Ismael and his friends after glimpsing Esmeralda's face lit up on a passing billboard.

Pool 2 explores the secondary but essential storylines of Underworld, beginning with J. Edgar Hoover receiving news of the Soviet nuclear test during the famous baseball game. It traces Marian Shay's affair with Brian Glassic from their first flirtatious meeting at a car show to their charged secret trysts, and follows the obsessions of characters like Matt Shay and Marvin Lundy who each seek meaning in footage and memorabilia. The Bronx is a recurring setting — its streets revisited by Matt, Bronzini, and the graffiti artist Ismael, each finding the neighborhood transformed beyond recognition. Klara Sax's early artistic struggles take her through the city in search of the elusive Moonman 157, while Matt and Janet's camping trip forces a reckoning with his disillusionment about his weapons career. The pool closes in the epilogue with Sister Edgar's profound emotional breakthrough after glimpsing a vision of the murdered Esmeralda on a passing billboard.

The lives on the margins — relationships, obsessions, and the changing city.

Bill Waterson chases Cotter through Harlem demanding the baseball but stops cold at the edge of the Black neighborhood.

Nick's mother moves in and tells Marian details about Nick's absent father Jimmy that Nick himself refuses to ever discuss.

Nick wakes in the night, grips the baseball, and climbs to the roof alone to listen to a radio baseball game.

Marvin Lundy receives a phone call from an unknown buyer in Phoenix and agrees to sell the Bobby Thomson baseball.

Sister Edgar learns from Brother Mike that a twelve-year-old girl named Esmeralda has been living alone in the ruins of the Bronx.

Richard, revealed to be the Texas Highway Killer, calls a television news anchor from a stranger's empty house to insist on his own normalcy.

Nick and Big Sims tour a mile-wide engineered landfill crater at night with their boss and waste consultant Jesse Detwiler.

Marvin and his wife Eleanor travel to San Francisco to meet Chuckie Wainwright about the baseball, but he never steps off the ferry.

Nick confesses to Marian that he had an affair with Donna at the waste conference, and Marian weeps silently while driving.

Klara Sax watches the Zapruder film of the Kennedy assassination over and over with Miles Lightman and immediately ends their relationship.

Father Paulus teaches a young Nick at the Jesuit facility that everyday objects contain hidden names and realities people cannot see.

Nick drives Amy to a clinic in Mexico for an abortion, privately doubting the decision but staying completely silent throughout.

Rosemary privately acknowledges that Jimmy actually hid his bet slips in his clothing, shattering the legend that he never wrote anything down.

A young Nick Shay asks Klara for a cigarette in the street, and days later she opens her apartment door and they become lovers.

Esmeralda is raped and thrown from a rooftop, and the news leaves Sister Edgar devastated and disillusioned with God.

Pool 3 focuses on the revelatory and decisive moments scattered across Underworld's nonlinear timeline. It opens with Cotter's escape into Harlem — a small moment that exposes the racial geography of 1950s America — and moves through a series of hidden truths uncovered or deliberately suppressed. Nick's mother inadvertently reveals facts about his absent father Jimmy that Nick refuses to discuss, while Rosemary's private knowledge that Jimmy faked his perfect memory dismantles the legend his sons have constructed around him. The pool traces Nick's emotional silences — his inability to voice doubts during Amy's abortion, his belated confession to Marian about Donna — alongside Klara's decisive break from Miles after watching the Zapruder film. Father Paulus teaches a young Nick to see the hidden reality lurking in everyday objects, and the pool closes with Esmeralda's brutal murder, the event that finally shatters Sister Edgar's emotional armor and briefly restores her faith.