Only Murders in the Building season 4 finale recap and ending explained

After how episode 9 of Only Murders in the Building ended, we knew we’d be in for quite an eventful season finale, and boy the finale did not disappoint. 

To recap, in the penultimate episode, we learned that Sazz’s protege was none other than Marshall, who earlier in the episode killed Glen Stubbins in order to keep him quiet. The final moments also saw Mabel discovering a script for the Only Murders movie which was written by Sazz, hinting that Marshall stole the script and perhaps it factored into his potential motive for killing Sazz. But did Marshall really kill Sazz and what exactly led to her death? Well, the finale answered those questions while also leaving us with a cliffhanger that has us very eager for season 5! 

Before we start breaking down the finale, let me use this moment to warn you that spoilers for Only Murders in the Building season 4 episode 10 are ahead. 

As the finale begins, we flashback to the past as Sazz ponders the next chapter of her life which comes in the form of writing the draft for the Only Murders movie, before we then return to the present day. 

Charles and Oliver return to Charles’ apartment, and the pair start to spiral about who might be the next victim realizing that every time they solve one crime, another body tends to drop. With Oliver’s wedding coming up, he begins to spiral about Loretta potentially becoming the next victim but he’s broken out of his spiral when Charles gets a text from Mabel that threatens, “Call the police or come anywhere near her door and I’ll kill her.” 

Charles races to the window, and he sees Mabel standing in the window with Marshall as Marshall closes the blinds.

Who killed Sazz on Only Murders in the Building? 

Mabel attempts to make an excuse to leave which is when Mabel pieces together Marshall was Sazz’s protege, and that he killed Sazz and stole her script. If there was any doubt that Marshall was the killer, he confesses to Mabel that he only meant to kill Sazz but then he had to kill Glen as well in order to keep his secret safe. 

Marshall tells Mabel that he has to kill Mabel now, but she quickly pivots the conversation to the script rewrites by distracting his attention by calling out mistakes in his script. It’s a brilliant tactic to help buy some time that works as Marshall agrees to hold off on killing Mabel until they finish the edits to the script. 

We then pivot to Charles realizes that the ledge connecting the apartment windows is the key to how he pulled off the murder and explains the footprint on the window. Charles gets the idea that they can use the ledge from Vince’s apartment to sneak in via the window to surprise Marshall and save Mabel. 

The duo races over to Vince’s apartment and asks for help using his window to get to Mabel’s apartment. Pulling inspiration from Sazz, Charles heads out on the ledge and begins making his way to Mabel’s apartment which is when Oliver joins him on the ledge as the pair begin slowly making their way over to the apartment as they can’t risk losing Mabel. 

While Charles and Oliver make their way over, Vince and Rudy lend the pair a hand in serving as a ding-dong to distract Marshall which gives Charles and Oliver the chance they need to sneak into the apartment undetected. Using Eva Longoria’s multitool, Charles manages to get the gun away from Marshall and turns the table on him as they question him about the motive. 

Why did Marshall kill Sazz?

Marshall goes on a rant about how he came to Hollywood to pursue his dreams of writing and that Sazz was the first person who believed in him. After he got kicked off the movie, she offered to read his screenplay and return to writing which is when she showed him her script for the Only Murder movie script. Much to Marshall’s shock, Sazz’s script was better than anything he had written and out of envy he told Sazz the script wasn’t any good. 

After stealing the script and making some changes, Marshall sent it out and Bev greenlit and fast-tracked the film which Sazz caught wind of. She called him over to her apartment to confront him about stealing her script from her. Sazz told Marshall that she was going to fly out to see Charles makes his Broadway debut and then tell him about the movie before she kicked him out of her apartment. 

From there, Marshall decided that the only way to save his career dreams was to kill Sazz. He made his way to New York, broke into Dudenoff’s apartment, and waited for his chance to use his hunting skills to kill Sazz using a sniper rifle. She didn’t die right away so he used his stunt training to use the ledge to maneuver around the building to Charles’ apartment where he watched her die and then disposed of her body. 

Following his confession, Marshall manages to get the gun back and begins spiraling holding the group at gunpoint. It looks like there is no out which is when Marshall is shot and killed through the window which is when the group spots Jan from Charles’ apartment. It turns out, she had never left the apartment and was hiding out waiting for them to figure out who killed Sazz so she could seek her revenge. 

Jan is arrested, Sazz’s killer is dead and there’s apparently only one thing left for the Only Murders team: head to the movie set it seems. 

Charles, Oliver, and Mabel head to the set of the Only Murders movie where they watch Eva, Zach, and Eugene filming the movie. Between shoots, Bev approaches Mabel about her next project which is when Mabel tells Bev she’d love to tell the story of a stuntwoman who did everything she could to protect her friends. Bev isn’t exactly sold and Mabel tells her perhaps she isn’t meant for this world. 

Charles then gets the chance to say goodbye to Sazz on the set before we head back to the Arconia for an Only Murders wedding! 

Only Murders in the Building season 4 finale ending explained

Oliver and Loretta’s special day arrives as they share their big day surrounded by loved ones with a beautiful ceremony fittingly hosted at the Arconia. During the reception, Loretta and Oliver share a sweet dance away from the group which is when Loretta tells Oliver that she can’t ask him to leave New York behind to move with her to New Zealand where her show is being relocated to, as there’s no way he could ask her to leave Charles and Mabel behind. 

After the wedding, Charles and Mabel head upstairs which is when they’re greeted by a mystery woman, played by the amazing Téa Leoni, who has come looking for them. As she tells the pair, she’s come to hire them to help her find her husband, Nicky Caccimelio.

Mabel and Charles tell her they only investigate murders that happen in the building which is when the woman tells them what happened to Nicky has everything to do with the building. They again turn her down which disappoints her as she gives them her business card and we learn her name is Sofia Caccimelio. 

We skip ahead to the next day as Loretta says goodbye to Oliver as she heads out, while Charles and Mabel put the final touches on the latest podcast. The trio think they’ve made it through a day without any murder which is when they stumble upon Lester’s dead body in the hotel fountain as the season ends.

And with that, it seems we have an idea of where season 5 will go. Solving Lester’s murder is sure to be the primary case of the season, while the mystery revolving around Nicky Caccimelio is clearly going to be the show’s secondary storyline. 

Another season of mystery and mayhem awaits us in 2025 when Only Murders in the Building returns. In the meantime, we’re going to have several months to ponder who might have wanted Lester dead and just what the story is behind Nicky and Sofia Caccimelio!

Only Murders in the Building seasons 1-4 are streaming on Hulu!