Melvin points out eight “weeping widows” (112) in the front row that they presume are Matthew’s former girlfriends. Gordon, seated behind them, says Matthew’s number was 29. The funeral is brief, with Matthew’s boss giving a eulogy and his girlfriend, Robyn, delivering a rehearsed speech. After, the group files into the bar area.

Tristan notes Melvin’s new appearance, which Melvin credits to a colleague named Christian. Vivienne asks after Mary; Melvin says she has had chemo treatments recently but is doing better. Janet struggles onto a barstool, and Melvin helps her up. As Tristan thinks about his last several Sundays spent helping Vivienne with her blog, he notes how he is beginning to like her. He is brought back to the present when Janet mentions only being able to find one of her leather gloves, earning Tristan an alarmed look from Vivenne.

Melvin reveals that after the others left the wine bar, Matthew admitted his number was 29 and was terrified. Tristan’s thoughts spiral to his own funeral and Ellie, triggering a racing heart and panic. He flees outside and crouches behind a plant. A man named Gareth Atkinson finds him and introduces himself as Matthew’s former schoolmate. Gareth admits to bullying Matthew at school and says Matthew had a difficult childhood. Vivienne finds Tristan and leads him back inside.

Gordon observes Tristan’s distress, puzzled since he didn’t think the two were close, as the group begins discussing the deaths. While Melvin notes that a stressed banker dying by suicide is not uncommon, Vivienne reveals that she is considering whether everyone is being married. However, Tristan suggests the numbers could simply be a “self-fulfilling prophecy” (124). In response, Gordon presents his theory that they are part of a social experiment, comparing it to the Stanford Prison Experiment. Vivienne dismisses the theory as unethical, then brings up the strange animal illustrations from the dinner party, recalling specific animals for each guest.

Gordon recalls lying to his wife, Elizabeth, about seeing a counselor named Dr. Leonard McCoy, a Star Trek character, which led to his current estrangement from his family. He believes a “secret scientific society” has chosen him for an intellectual “challenge” to join their group (129), though he doesn’t share this with the group.

Gordon asks who is next, pointing out that Janet’s number is 44 and she has less than four months to live. A drunk Janet declares she will enjoy her time and joins a group of young bankers. Gordon presses the others for their numbers. Tristan reveals his is 45, while Vivienne confirms she hasn’t found her envelope and Melvin says he left his at the restaurant. Gordon, who has Melvin’s envelope in his pocket, decides not to reveal it. Instead, he leaves, saying he has work to do.

Janet approaches the bankers’ table and attempts to flirt with a man named Jonathan, but his colleagues reveal he is a devoted family man. The conversation triggers a flashback to Janet’s traumatic stillbirth and emergency hysterectomy. She overheard her husband, Bill, say afterward that it was for the best, filling her with lasting anger toward him and the world.

Feeling rejected, Janet rejoins her group and finds her missing leather glove on the table. Vivienne reveals she found it on the rooftop of Matthew’s office building. Janet lies that she had a meeting nearby and saw Matthew arguing with someone but never went to the roof. Vivienne accuses Janet of murdering Stella out of jealousy and then killing Matthew when he rejected her. Janet laughs off the accusation and counters that Vivienne could be the killer, pointing out the convenience of her lost envelope. She storms away.

Melvin follows Janet outside and tries to comfort her. Janet alludes to Melvin’s closeted sexuality, which he confessed to her after the dinner party. Melvin grabs Janet’s wrist violently, threatening her to keep quiet. Unintimidated, Janet tells him she can “spot” an affair and that his “won’t end well,” then promises to “see [him] in hell” before leaving in a taxi (141).

Melvin returns to the table, shocked at his violent behavior toward Janet. He reflects on Christian’s makeover and feels foolish. A flashback reveals that on the night he planned to tell Mary about Christian, she announced her cancer had returned, so he couldn’t confess. Melvin and Christian then began an affair.

In the men’s room, Melvin is disgusted with himself, wondering what his late father would think. He recalls a recent dark moment when he contemplated smothering Mary with a pillow to end her suffering and his guilt but stopped himself. He rejoins Vivienne and Tristan. Vivienne talks about her lost envelope and her fear. Melvin receives a text from Mary reminding him of her support group meeting, then he leaves.

Six months later, in August 2016, Vivienne arrives home to the happy “chaos” of Cat and her son Charlie, who now live with her. The magazine has closed. After Cat’s landlord raised her rent, Vivienne offered them a place to live, feeling her time might be short. At the same time, however, she experiences new aches and pains and worries they signal approaching death. During dinner, Cat asks if she is feeling better after a recent fugue state, which Vivienne has passed off as a hangover. She remains consumed by the investigation, yet the emails from Melvin have stopped and she’s found no new information.

After Matthew’s memorial, Tristan became withdrawn, but Vivienne staged an emergency to get him to meet her. Tristan told her that he experienced panic attacks, worsened by his breakup with Ellie and a gang assault on a night bus where a police officer failed to intervene. Despite this, he promised to continue to help Vivienne, and her blog has become successful.

Tristan arrives unexpectedly with news: Janet Tilsbury has died after being hit by a taxi, just three days before her 45th birthday. Vivienne realizes with horror that Janet died at 44, matching her envelope. That night, unable to sleep, she researches the animal drawings from the dinner party and discovers they represent the seven deadly sins. She matches each guest to a sin: Janet is Gluttony, Matthew is Lust, Stella is Greed, Gordon is Pride, Tristan is Wrath, Melvin is Sloth, and she is Envy. She theorizes the host, the devil in the drawing, is the killer.

A week later, Vivienne and Tristan attend Janet’s wake at a pub called the Royal Oak. A drunk colleague gives them a memorial program. Vivienne spots a man she presumes is Janet’s husband, Bill, laughing loudly at the bar.

Tristan observes the wake, reflecting that Janet always treated him poorly. Melvin arrives, appearing unusually upbeat, and buys cocktails. Tristan recalls his reaction to seeing Ellie’s relationship status change online. In flashback, he staked out Ellie’s house and saw her pregnant, arguing with her new boyfriend, Dale. Overcome with rage and regret, he kicked the mirrors off cars on his way home. When Vivienne encouraged him to meet his old friend Dave, Tristan went to the pub but couldn’t go inside. He later lied to Vivienne that it went well.

Melvin reports that Janet’s death was ruled an accident with no CCTV. Gordon arrives, then Bill comes to the table. Tristan notes that she looks genuinely upset up close. He reveals that no one knows why Janet was in Notting Hill when she died, prompting the group to discuss whether she had a secret lover. Janet’s sister, Caroline, then approaches with her baby, Tabitha, and her husband, Giles, to introduce themselves. After they’re gone, Gordon asks Vivienne if she has found her envelope.

Gordon is irritated by the group and obsesses over germs on the table. Tristan snaps at him for admonishing Vivienne about her lost envelope. In flashback, Gordon details his new life. He has left Elizabeth and Louisa and moved into a sterile white flat to focus on his longevity experiment. He has whiteboards tracking “Experiment Serendipity” and his own Experiment 54. He follows a strict calorie-restricted diet and rigorous exercise plan to fight his number of 53. His boss has taken a surprising interest in his research, making Gordon suspect he is part of a secret society. Gordon admits to periodic binges on junk food, which he then purges, blaming the stress of Elizabeth’s phone calls.

In the present, Melvin asks about Gordon’s daughter, Louisa. Gordon recalls a recent awkward meeting where she questioned the point of living longer if he was alone. Gordon gives Melvin the envelope he took from the dinner party and offers him a paper summarizing his longevity research. Melvin dismisses the research, saying he will let fate run its course. Disgusted by Melvin’s lack of interest and perceived weakness, Gordon tells him he has “blown it” and storms out of the pub.

Melvin watches Gordon storm out and shrugs off the envelope as unimportant. Tristan quotes that “evil exists when good people fail to act” (184), then leaves abruptly. Melvin invites Vivienne to another bar. There, he texts a lie to Christian, who is waiting for him. Melvin reveals that the first person on the scene of Janet’s accident was her brother-in-law, Giles, confirming their affair.

Vivienne explains her seven deadly sins theory, identifying Melvin’s sin as sloth, which he interprets as inaction. She reveals her sin is envy, described as “rottenness of the bones” (189), then comments on the possibility of a horrible death. To appease her, Melvin agrees to contact the landlord of Serendipity’s again for information about who hired the venue.

Vivienne insists that something is wrong, and Melvin confesses he is having an affair with Christian. He explains that Mary’s cancer is now in remission, but to his horror, Mary and Christian have become close friends. Vivienne bursts into laughter at the predicament, and Melvin joins in. He suspects they are planning a surprise party for his upcoming 60th birthday.

Vivienne encourages him to tell the truth and suggests they open his envelope. She opens it for him and reveals his number is 61 Melvin feels that two more years of his current life sounds too long. Vivienne asks to keep the envelope as a “clue.” While she is away from the table, Melvin checks his phone and sees a text from a man he had a one-night stand with the previous night after drinking and drugs. He deletes the message before Vivienne returns.