This post contains spoilers from Only Murders in the Building season 5 episode 1 from this point forward.
Charles, Oliver, and Mabel are back in Only Murders in the Building season 5 with a brand new murder mystery, and this might be their biggest case yet! The end of season 4 saw the trio discovering the body of their beloved Arconia doorman Lester Coluca (Teddy Coluca) in the courtyard fountain. Previously, Charles and Mabel were approached by Sofia Caccimelio (Téa Leoni) to find her missing husband Nicky, the "dry cleaning king" of Brooklyn.
The season opens before Lester's wake in the lobby with Charles, Oliver, and Mabel discussing Lester's obituary and the fact that the police have already declared his death accidental as Oliver munches on leftover shrimp from his wedding. They aren't convinced that Lester's death was accidental, but Howard suggests that security footage confirms that he wasn't murdered. Mabel notices that Oliver isn't holding a shrimp this time... It's a severed finger!
Oliver tosses the finger behind him in fright, and it lands on the piano. They inspect the finger, with Mabel bravely picking it up, and they notice what looks like green fungus on the nail. When Oliver calls the severed finger "very mobby," Mabel suddenly remembers Sofia Caccimelio looking to hire them to find her mobster husband Nicky (Bobby Cannavale). Their next working theory is to check Lester's coffin to confirm he had all his fingers.
Nicky Caccimelio becomes a suspect in Lester's murder
Lester's funeral in the Arconia lobby is a curious event as it's attended by Mayor Tillman (Keegan-Michael Key), and Lester's wife Lorraine (Dianne Wiest) has heard about Oliver in particular. Lester apparently referred to him as the "Cuckoo Chick." Lorraine gives Randall (Jermaine Fowler) the new doorman Lester's sacred Arconia ledger as Mabel and Oliver approach her. Charles gets the mayor's card and pokes around the casket to check fingers.
Mabel gives an impromptu speech to give Charles an even longer distraction. Unfortunately, Charles doesn't get the information they need and he also gets caught by the entire party. Looking to make up for his snafu in forgetting to share a photo with Lester, Oliver tracks one down from his wedding day... only it's a closeup of Oliver with Lester far in the background being handed an envelope by Nicky Caccimelio. New theory: Nicky killed Lester.
Before getting the courtyard security footage from Howard, the trio heads to Staten Island to pay Sofia Caccimelio a visit. Mabel brings the finger along in a drink tumbler to the Caccimelio home, which is the house from The Godfather. They're immediately unsettled by Sofia's five adult sons, who question them and pull out a gun. But it's not a gun, it's a Bluetooth speaker made to look like a gun as merch for their podcast. It's all a huge misunderstanding.
Sofia didn't send them the finger, but they want to know why Nicky has "everything to do" with their building. They show her proof that Nicky was at the Arconia talking to Lester just the other day. She insists that the mob isn't active and claims that Nicky was dropping off receipts for the dry cleaner business they own in the Arconia. Sofia confirms the finger isn't Nicky's, and after the trio leaves, she seems to flirt a little bit with Charles and gives him a deck of Nicky's cards.
Finding the secret casino and Nicky's body
Later that night, Charles seems to have some doubts about his future, especially after seeing Oliver so happy to talk to Loretta on the phone. While having a glass of red wine and playing with the cards, Charles discovers a secret map written on a card that's magnetized. Mabel checks the security footage of Lester and notices some footage is missing. Charles follows the map on the card and runs into Mabel, who's checking the security cameras.
The map leads them through all of the blindspots from the security footage and to a closet in the lobby. Mabel opens a trap door behind a utility shelf. They walk down a creepy flight of stairs under the building and use the playing card to unlock another door. Inside, they find an expansive underground casino. Mabel uses the numbers on the playing card to spin the roulette wheel and open a secret drawer containing the envelope of money with a splatter of blood.
While Mabel and Charles confirm that Lester's death wasn't an accident, Oliver takes Lester's hat to the dry cleaners as means to make himself look good to Lorraine. The door to the closed and dark shop was unlocked, so he let himself in. Upon seeing Lester's uniform, he turns on the spinning racks to retrieve it, and it's in that moment that Oliver happens upon Nicky's dead body. Suddenly, there's a second murder in the building for the start of season 5!