With a Vengeance

With a Vengeance is a 2025 murder mystery novel by New York Times bestselling author Riley Sager. Sager is the author of nine mystery and suspense novels, including Final Girls, The Last Time I Lied, Lock Every Door, Home Before Dark, Survive the Night, The House Across the Lake, The Only One Left, and Middle of the Night. His books are published in 35 countries and have sold over 3 million copies globally. Sager’s works often explore isolation, revenge, and legacy. In With a Vengeance, former railroad heiress Anna Matheson works to enact justice upon those who worked to destroy her family and their legacy. Anna lures the conspirators on a journey from Philadelphia to Chicago aboard her father’s former train, the Philadelphia Phoenix, to force them to face the impact of their actions. With a Vengeance examines The Difference Between Revenge and Justice; The Pursuit of Truth and the Gray Areas of Morality; and Guilt, Redemption, and the Weight of the Past.

This guide refers to the 2025 Hodder & Stoughton Kindle Edition of the source text.

Content Warning: The source text and this guide feature discussions and depictions of graphic violence, death, death by suicide, substance use, emotional abuse, and antigay bias.

Plot Summary

The novel opens in media res—amid action rather than at the start of the chronological sequence—as the conspirators and Anna stand around a dead corpse and wonder what happened. In a flashback to 1954, Anna Matheson gathers Jack Lapsford, Sal Lawrence, Kenneth Wentworth, Herb Pulaski, Edith Gerhardt, and Judd Dodge aboard the Philadelphia Phoenix, a 1937 luxury train from Anna’s father Arthur Matheson’s railroad company Union Atlantic. Anna sent them invitations with personalized notes ensuring their attendance. Anna blames these individuals and seeks justice for the destruction of her family. Anna and her friend Seamus Callahan have a plan: She paid off the train’s employees and bought the other tickets to ensure the only passengers are the six invitees, Seamus, the train’s engineer, and herself. The train will not stop until it reaches Chicago, where the FBI will arrest the six people. She wants them to realize their lives are over while trapped on the train for 13 hours.

At cocktail hour, Anna realizes that Kenneth’s invitation was intercepted by his son, Dante, whom Anna had a relationship with. Anna tells the group why they’re there. In 1942, a Union Atlantic train carrying new soldiers exploded outside Raleigh, North Carolina. Aboard was Anna’s brother, Tommy Matheson. Thirty-seven men died, including Tommy and Seamus’s brother, Sean. Arthur Matheson was arrested and blamed for the explosion. Before he could face trial, he was stabbed to death in prison, 37 times for the 37 dead men. Anna’s mother soon died by suicide, and Anna was sent to live with her Aunt Retta. Retta maintained Arthur’s innocence until her death.

Seamus revealed evidence that proves how the people aboard the train worked to destroy Anna’s family. Jack, a retired lieutenant colonel, approached Arthur about providing the train but falsely testified that Arthur approached him. Judd designed the faulty locomotive to explode. Herb oversaw the construction of the faulty locomotive. Sal Lawrence was Arthur’s secretary, and she falsified memos and documents incriminating Arthur. Edith was the Matheson’s housekeeper, and she hid documents incriminating Arthur and alleging that he was a Nazi sympathizer. Anna explains that Kenneth, Dante’s father and the owner of a rival railroad company, orchestrated this. After Arthur’s arrest, Kenneth bought Union Atlantic and made a massive profit, which he shared with the conspirators. Anna tells the group that the train is going to Chicago, where the FBI awaits. The group unsuccessfully tries to stop the train by pulling on the handbrake and begging the engineer to stop.

Anna shows the group Judd’s original plans for the faulty engine. Jack unsuccessfully fakes a heart attack to get Anna to stop the train. Judd collapses and dies, seemingly from a poisoned cocktail. Dante made all the cocktails in the same shaker. Seamus searches the men for poison, and Anna searches Sal and Edith. Edith tells Anna that her family would be disappointed in her, and Anna nearly strangles Edith.

A mysterious man enters the lounge car and introduces himself as Reggie Davis, an insurance salesman who got on the wrong train. Reggie is horrified to see Judd’s body, but at the insistence of the group, he searches Anna. He feels Anna’s concealed knife but doesn’t comment on it. He searches Seamus and reveals Seamus’s gun. Seamus and Anna tell everyone to stay in their cabins with the doors locked. She promises Reggie that Seamus will guard his door.

Anna searches the train for poison. She finds Dante in the galley car, and they reminisce on their past relationship. Dante apologizes for ending their relationship at his father’s insistence. He says that he didn’t know about his father’s plot. Anna finds rat poison. She gathers everyone in the observation car, a car made of floor-to-ceiling windows, and reveals the poison. No one claims to have entered the galley car or to have seen anything. Anna falls asleep. When she wakes, Edith confesses to seeing Jack lingering in the galley car. Anna asks Edith if she ever loved her and Tommy, and Edith says their relationship was real, but Edith’s loyalty to Nazi Germany and Kenneth’s blackmail swayed her. Anna tells Edith that she hopes she’s haunted by regret. She thinks she sees her brother Tommy, but he disappears.

Anna checks each cabin for Tommy, but when she returns to the observation car, she finds Edith dead. Edith appears strangled with a curtain cord, but Reggie notes that her lipstick is smudged, and she has no ligature marks on her neck, indicating she was smothered with a pillow. The cord was placed around Edith’s neck postmortem to cast suspicion on Anna. Reggie reveals himself as an FBI agent, sent by his boss Ed Vesper to ensure that Anna’s plan doesn’t turn lethal. Reggie lost his father in World War II, so he feels for Anna but blames her for the dangerous situation.

Reggie and Anna interview everyone about Edith’s death. Anna thinks she sees Tommy again. When she chases him into the lounge car, she realizes it’s Herb, who holds her at knifepoint and demands that she stop the train. Anna fights Herb off and holds her own knife to his neck. Seamus interrupts her and takes Herb to his cabin.

Dante tells Anna that this is his fault. Dante was the one who sent Anna the evidence, as he dislikes his father. Dante tells Anna that Kenneth destroyed her family for revenge; Kenneth was once engaged to Anna’s mother, but Margaret left him for Arthur.

Sal admits to having heard rumors about Margaret and Kenneth. Sal confesses that Kenneth sent a woman to seduce Sal and take photos of it for blackmail. Sal cautions Anna about Seamus, whom she finds suspicious. Anna talks to Seamus about their future, which they both find uncertain. They notice blood on the floor and enter Herb’s cabin. Herb’s throat is slashed. The killer must have used the window to climb onto the roof to move between cabins unseen. Seamus finds Anna’s pin on the floor, which makes the group suspicious of her. Anna invites the group to search her cabin. They find the window open and a curtain cord missing.

Reggie sends everyone else back to their cabins while they consider who is framing Anna. Anna realizes that Judd never actually drank from his supposedly poisoned drink. Judd faked his death. When the group returns to Judd’s cabin to check on his corpse, he’s gone. The group splits up to look for Judd. Reggie and Anna go together, and Reggie gives Anna his jacket with his gun. Reggie is stabbed by Judd while Anna isn’t looking. Anna sews him up, and Reggie reveals his father was murdered and the killer never caught, which is why he joined the FBI. Reggie falls asleep, and Anna has a vision of Tommy before fainting.

Dante wakes Anna, and they nearly kiss before Seamus interrupts, appearing jealous. Seamus and Anna slept together once. Seamus shows Dante and Anna where he found Judd’s corpse stuffed in a lavatory. Anna searches Judd’s body and finds the remnants of a handmade fake blood capsule in his mouth and rat poison in his watch. Anna realizes there’s another killer on the train.

Anna confronts Jack and Sal. Jack fakes another heart attack, though it seems real. Seamus offers him a muscle relaxant, a medication he takes for his degenerative condition that gives him spasms. Anna takes the pill and withholds it from Jack until he confesses to destroying her family. Anna confronts Seamus about hiding his condition from her. Anna promises to find him a good doctor. Seamus realizes his gun is gone, and they hear gunshots. When they enter Sal’s room, they find her dead. Anna accuses Dante of murder and confines him to his room.

Anna doesn’t think Dante is the killer, but she wants to protect him. She hears someone arguing with Jack in his cabin, and when she enters, she finds Seamus smothering Jack with a pillow. Seamus says that with his degenerative condition, he couldn’t wait to see the people who killed his brother pay for their crimes. He went along with Anna’s plan because he loves her. He tells Anna it felt good to kill someone, gives her his gun, then jumps off the train. Anna grieves Seamus but realizes that he only admitted to killing one person. Anna realizes the killer is  Reggie and discovers him in Jack’s cabin.

Reggie’s father was the engineer aboard the train that exploded, so Anna’s plan allowed him vengeance. Reggie realized Judd wasn’t dead, so he teamed up with Judd and picked off the conspirators. Anna tells Reggie she became suspicious after Reggie was supposedly stabbed by Judd—his shirt was changed, and the stab wound was on the wrong side of his torso. Reggie says that he’ll kill Anna if she doesn’t go along with his plan, but Sal sneaks up behind Reggie and knocks him out with a champagne bottle. When Anna became suspicious of Seamus, she plotted with Jack and Sal to out him. Jack faked his heart attack while Sal stole Seamus’s gun and faked her death.

Dante frees himself and checks on Anna. She gives him Seamus’s gun to protect himself, Sal, and Jack. Anna follows Reggie out the window and onto the roof. She points the gun at Reggie, who says she won’t shoot him. She lures him onto the glass roof of the observation car and shoots the glass. Anna and Reggie land in a heap in the observation car. Before Anna can shoot Reggie in the leg, the train stops. Anna and Reggie run toward the locomotive, which opens to reveal Kenneth Wentworth.

Kenneth thanks Anna for helping him eliminate his co-conspirators. Kenneth reveals that he destroyed Arthur, even paying an inmate to stab him to death, because Arthur stole Margaret and Kenneth’s son. Margaret was pregnant with Tommy when she left Kenneth for Arthur, and Arthur claimed Tommy as his own. Kenneth could never interact with Tommy, so he hatched a plan to destroy Arthur; he never intended for Tommy to be aboard the train. Anna is angry, and Reggie tries to goad her into shooting Kenneth. She pulls the trigger.

The FBI agents board the train in Chicago. They find Dante, Sal, and Jack in one car, and Reggie shot in the leg in another. Finally, they find Anna holding Kenneth at gunpoint. The evidence Anna sent ahead to Chicago is enough to put Kenneth, Jack, and Sal away, and Reggie confesses to killing Herb and Judd, taking the fall for Seamus. Dante and Anna decide to stay close. Anna promises to write to Dante to tell him about Tommy, their shared half-brother. Reggie’s boss, Ed Vesper, offers Anna a job at the FBI, which Anna accepts.