Only Murders in the Building: Season 4, Episode 10 - My Best Friend's Wedding (2024)

The episode opens with the season's central mystery finally coming into focus: Marshall is revealed as the person who killed Sazz, and the story circles back to the script for the Only Murders movie that Sazz had been developing and showing to others. The revelation ties Marshall's motive to fear that Sazz's work would expose that he had stolen her screenplay, destroying both his career and his relationship with his father.

Mabel is left alone with Marshall in her apartment after she finds the script among Sazz's belongings and realizes Marshall has been hiding the truth. While she keeps him talking, Charles and Oliver separately piece together the larger picture from earlier clues, including the fact that Marshall was Sazz's protégé and that he had reason to want her silenced.

As Mabel stalls Marshall, Charles and Oliver rush to warn her, but their efforts are delayed by the discovery that Charles is in immediate danger too. The trio's movements across the building and the apartment complex become a race against time as they try to reconnect before Marshall can act on his threat.

Inside Mabel's apartment, Marshall explains his version of events in detail. Sazz had been the one pushing the movie project forward, and Marshall had access to her material because she trusted him enough to let him read and work with the script. He stole her screenplay, feared exposure, and then killed her to keep her from revealing the theft to Charles and the rest of the trio.

The flashback sequence shows the murder setup: Marshall had come to New York after realizing the project was slipping away from him, and he used his knowledge of the Dudenoff apartment and the building layout to position himself for the shot. He fired through the window at Sazz when she entered Charles's apartment, matching the same method later used against him.

After Marshall finishes explaining the murder, Charles explodes in anger and throws the multitool at him, but misses. In the resulting chaos, Marshall regains control of the gun and turns the trio into hostages, threatening them while insisting the movie version of their story is now effectively his story.

Marshall begins to hold the trio at gunpoint in Mabel's apartment, but before he can finish them off, an unseen shot comes through the window and hits him. The bullet kills Marshall in the same way Sazz was shot, stopping the confrontation instantly.

The shooter is revealed to be Jan, who appears at the decisive moment and fires from Charles's apartment window. Her intervention prevents Marshall from killing the trio and resolves the immediate hostage crisis, though it also exposes that she has remained deeply connected to Charles's life in dangerous ways.

After Marshall is taken down, the episode shifts into the emotional and comic aftermath of the reveal. The trio is left alive but shaken, with the season's murder mystery solved and the truth about Sazz's death fully laid out: Marshall stole her script, feared the consequences of being exposed, and murdered her to protect his future.

Short version: Marshall is revealed as Sazz's killer, he traps Mabel, Charles, and Oliver, and Jan shoots him through the window at the last moment. Meanwhile, Oliver and Loretta still get married, and the trio survives the night, though Charles ends the episode heavily affected by the gas and the chaos.

Now the ending, scene by scene:

The finale returns to the building's central mystery and confirms that Marshall, also identified as Rex, was the man who killed Sazz. The reveal ties back to Sazz's screenplay, which Marshall had stolen, and to his fear that she would expose the truth and damage his career and his relationship with his father.

In the final confrontation, Marshall corners Mabel in her apartment and holds her hostage while Charles and Oliver race to reach her. He pressures the trio and threatens them as the situation narrows around them in Mabel's room, where the script and the truth about Sazz's death have finally converged.

As the standoff reaches its most dangerous point, Jan fires a shot from across the courtyard and kills Marshall through the window, stopping him before he can carry out his threat. The shot mirrors the way Sazz was killed and ends Marshall's role in the story immediately.

After that, Jan is arrested and taken away by police. Charles is loaded into an ambulance because he has been poisoned by gas and is in bad condition, while Mabel and Oliver remain standing after the chaos in the apartment.

At the same time, Oliver's wedding to Loretta goes forward at the Arconia. Loretta arrives late, the ceremony is interrupted briefly by the surrounding emergency, but the wedding still happens, giving Oliver a personal ending that contrasts with the violence of the murder case.

By the end of the episode, the main fates are clear: Marshall is dead, Jan is arrested, Charles survives but is taken for medical treatment, Mabel survives the confrontation, and Oliver completes his wedding to Loretta.

Yes. The episode ends with a post-credits tease rather than a full extra scene: after the season's main mystery is wrapped up, the final beat sets up the next murder by revealing that Lester, the Arconia's longtime doorman, is dead, with the show pointing toward his body being discovered after the credits roll.

The finale itself already closes on a cliffhanger-style reveal before the credits, with the trio facing danger and the season ending on another death inside the building. The post-credits implication is that this new murder will be the focus going forward, rather than adding a separate comedic epilogue or bonus scene.

Marshall's confession is tied to his history with Sazz and his resentment over losing credit for work he believed should have been his. The episode shows that after his stuntman career setback, he turned to writing, Sazz mentored him, and he later stole her script idea, turning that betrayal into the motive behind her murder.

Sazz had been developing a movie project based on the trio's podcast life and personal dynamics, treating it as a way to honor Charles, Mabel, and Oliver while also pursuing her own filmmaking dream. The episode frames the script as central because Marshall's theft of it explains both the emotional betrayal and the murder plot.

In the finale, Charles uses the dangerous situation inside the Arconia and an improvised weapon to confront Marshall after Marshall and another man break into Mabel's window. The scene turns into a direct showdown in which Charles pressures Marshall into explaining what happened to Sazz.

Mabel and Oliver investigate the Arconia's West Tower and end up trapped in an ominous game while the rest of the story is unfolding around them. Their separate peril helps build the episode's tension by splitting the trio and tying the finale's mystery to the building itself.

Oliver receives a text that Loretta is in the courtyard, and the episode includes a wedding-related courtyard reveal connected to Lester's past marriage there. This gives the finale its wedding motif and links Oliver's personal storyline to the episode's title and emotional backdrop.

No, it is not especially family-friendly for young children. For sensitive viewers, the main concerns are murder-mystery violence, threat and peril, some dark or tense suspense, and likely adult language and emotionally intense material.

Potentially upsetting or objectionable elements to expect: - Murder-related themes and discussion of killings - Characters facing mortal danger and hostage-like peril - Tense, suspenseful scenes with an ominous tone - Adult-oriented relationship and wedding material rather than kid-focused content - Some language and mature subject matter that one reviewer felt made the series unsuitable for younger children or even tweens

If you want, I can also give a very short age-recommendation style verdict, such as "okay for teens, not for kids."