Four fans of the "Only Murders In The Building" Podcast -- Arconiacs, as they call themselves -- have assembled outside the Arconia. They discuss the merits of the show and wonder if it will get another episode.
Theo drives his van to a dump, with Mabel, Oliver, and two corpses in the back. Teddy greets them when they arrive. Leaving the corpses at the dump, Theo drives them home. Teddy sits in the rear-facing position. He explains to Mabel and Oliver that he would appreciate their silence and that the podcast needs to end. Mabel accuses Teddy of murdering Tim, but he denies his and Theo's involvement. He threatens Mabel and Oliver, telling them to release a final episode tomorrow saying Tim committed suicide.
When Mabel and Oliver return to the Arconia, the fans greet them with excitement. They have a little exchange until Mabel drags Oliver away.
Oliver and Mabel head to Charles's apartment. Jan answers the door. She serves them coffee and Charles returns with bagels. Mabel and Oliver catch Charles up on the death threat from Teddy, as well as Teddy's instructions for the final episode.
Charles and Jan, having spent the morning going through Tim's phone, have made some discoveries. Tim kept meticulous records about everything. Jan and Charles tell Oliver and Mabel about how Tim saw Theo push Zoe off the roof. Tim had been working on bringing the Dimases down until he died. Mabel thinks this means they killed Tim, but Jan tells her not to jump to conclusions.
Mabel pulls Oliver and Charles aside, away from Jan, saying they need to take Teddy down before seven the next morning.
Down by the river, the trio meets with Detective Williams. They tell her that they have reason to believe Tim was murdered by the Dimas family. Detective Wiliams tells them she was hoping they would make a podcast episode with this information but understands that they don't want to be targeted. She tells them she is running a toxicology report and that if they want to solve the crime, they need to get the "who," the "how," the "why," and the "why now."
The trio gets to work. Jan arrives with homemade pizza rolls. Mabel and Oliver resent Jan for ingratiating herself into the investigation. Oscar shows up, with news about the case. He tells them that Cutter, the jewelry connection, told him that he had sold the green ring to Tim the day before Tim died. Mabel says the ring wasn't among Tim's things, so the Dimases must have taken it, citing this as the "why now." Jan doesn't agree, saying without the ring it's all circumstantial. Oliver goes out for some air and groceries.
On his way back, Oliver runs into some of the fans -- Sam, Paulette, and Marv -- and assures them that resolution is close. They ask him many intelligent questions and he invites them in to help.
The fans fawn over the team. Jan introduces herself, with Charles saying she's his girlfriend, and they have a moment.
Increasingly annoyed, Mabel takes Oliver and Charles aside again. Oliver insists that the fans will be helpful.
Sam brings up the point that Tim lived on the ninth floor, but on the night of his death, he got on, with a trash bag, from the sixth floor. Oliver notes that floor six is Teddy's floor. Paulette wonders if the trash belonged to Tim or Teddy.
Jan brings up Evelyn the cat and Howard Morris. Everyone except Charles shoots her down. Oliver suggests that Tim's "suicide" notes were actually death threats from the Dimases.
Oliver stages a flashback re-enactment, with Paulette as Lester, Marv as Theo, and Sam as Tim Kono. Sam/Tim enters and asks Paulette/Lester about a package. The fire alarm goes off. Marv/Theo pushes his way into Sam/Tim's apartment. They fight and Marv/Theo shoots Sam/Tim. Marv/Theo types the suicide message on Tim's computer.
Charles thinks the theory is confusing. Jan says it feels too easy.
Mabel and Oliver decide to start recording and they insult Jan for her rotten ideas. Jan leaves, upset.
Upon returning to her apartment, Jan finds a note on her door that says "I'm watching you." Rattled, she quickly enters her apartment and shuts the door.
Charles finishes recording the final voiceover for the last episode. The fans are delighted to have participated. They say their goodbyes and leave.
The trio sends the episode to Detective Williams before sending it out for wide release. As the podcast episode shows up on Teddy's phone, Detective Williams shows up at his door, with backup, ready to take him and Theo in.
Everyone is listening -- Lester, Uma and Bunny, Will and Winnie, and the fans. Grant, the fourth Arconian who'd had to leave because of a piano lesson, questions why the Dimases would have sponsored a podcast that they knew might out them. Sam suggests hubris.
Mabel, Oliver, Oscar, and Charles celebrate their victory. Charles texts Jan his apology but receives no reply.
Mabel shows Oscar a video of Tim, in which he details the work he's been doing to bring down the Dimases for Zoe's death. In the video, Tim apologizes for his silence about Oscar's innocence.
Detective Williams and Oliver have a chat on the phone. She tells him that the Dimases will go down for Zoe's death and for the grave-robbing. The toxicology report returns, indicating that Tim Kono was poisoned -- he was dead before he was shot. Furthermore, there are photos of the Dimases outside the Arconia before the fire alarm when off. Enraged, Detective Williams hangs up. Oliver relays this new development to the team.
Charles is upset he didn't listen to Jan. He buys her some flowers and goes to her apartment. The door is open. Jan is lying on the floor, unresponsive, bleeding from a serious-looking wound.