Only Murders in the Building is a hit with viewers and critics.  The series centers around three very different people: Charles-Haden Savage (Steve Martin), the star of a crime television show that’s long been off the air; Oliver Putnam (Martin Short), a stage director with a reputation for crafting legendary flops; and Mabel Mora (Selena Gomez), a young artist with a mysterious past.  Though the trio are an unlikely set of friends, they are brought together by a shared passion for true crime podcasts, and when one of the residents of the Arconia– their luxury New York City apartment building– dies, they don’t accept the police’s verdict of suicide, and they start their own investigation… and their own podcast.

Each of the previous seasons investigates a different murder at the Arconia, with the killer being revealed in the final episode of each ten-episode season, and the final moments of each season finale setting up the next season’s mystery.  It’s an extremely enjoyable series with a terrific cast and well-crafted mysteries.  However, the show has built up a considerable collection of dangling plot threads and minor characters that has grown ever-larger with each passing season, and hopefully, the next season will start tidying up some of the sidelined details before they become too unwieldy to address in a satisfactory manner.

The release date for season four has yet to be announced, but here are five things to hope for when it finally returns.  (Warning: Oblique spoilers follow)

1.     Another Solvable Mystery

One of the most enjoyable aspects of the show is that all of the season-long mysteries are solvable.  Little clues are introduced into the series in subtle ways, and the observant viewer can figure out whodunit by the next-to-last episode of each season.  There’s one problem that makes some of the solutions a little too obvious– each season tends to keep the guilty party largely unsuspected until right before the final accusation.  It leads to a problem that hurt the American version of The Killing– an episode or two would be spent suspecting one character, only for that person’s innocence to be revealed, crossing a name off the suspect list.  In the best whodunits, like Agatha Christie’s, it’s possible to learn about all of the suspects and suspect everybody, and still consider every character a viable suspect until the end, when a thoroughly satisfying and surprising killer is revealed.  Hopefully, in future seasons, the mysteries can avoid the trope of making it easy for the viewer to guess the suspect by picking a character who has never been previously suspected.

2.     Great New Supporting Characters… As Well As Familiar Faces

Only Murders in the Building has built up a collection of dozens of characters, many played by Broadway stalwarts.  By the end of season three, there are three or four dozen recurring characters.  Some of them can be cut from the show without being missed, but others have become an integral part of the series, even if they are largely background characters.

In seasons one and two, most of the residents of the Arconia were viable murder suspects.  But by the end of season three, the same issue that affected Veronica Mars’s cast has come into play.  In the first season of Veronica Mars, all but three members of the cast were viable suspects.  But by the second season, viewers had come to know and care for all of the cast, and given the emotional bonds the audience had with these characters, they were no longer viable potential murderers, so new suspects had to be brought in for later seasons, growing the cast and sometimes taking screen time away from fan favorites.  On Only Murders in the Building, for example, cat aficionado Howard Morris (Michael Cyril Creighton) was a suspect in the first two seasons, but by season three, he’d been promoted to a main cast member, and given his growing role, no longer made a viable suspect, as growing audience affection for his increasingly developed and comedic character would have made making him a murderer unsatisfying (and the series has done a great job of selecting very satisfying choices in the roles of killers).  Therefore, the series must deal with the challenge of introducing new suspects into the narrative while still giving the old favorites something to do.

As of this writing, Eugene Levy, Molly Shannon, and Eva Longoria have been cast in season four, with more casting announcements to come in the future.  The show will have a difficult balancing act juggling all of these characters, but based on the past few seasons, fans have reason to be optimistic.

3.     Redemption Arcs

In season one, a major subplot was a death that had taken place a decade earlier, leading to an innocent man being sent to prison.  The real perpetrator is revealed midway through the season, but by season two, when the character is reintroduced, it’s argued that the decade-old death was an accident, and that the perpetrator is actually not a bad person at all.  It’s a nice touch, as Mabel gets to know someone she previously loathed, and gradually befriends that person.  Yet while the character in question may not be a cold-blooded murderer, that person did allow a blameless person to go to jail, and so far, has not taken steps to right that wrongs.  Similarly, it’s implied that the killer in season three is not a vicious murderer, and could also become a decent person if given the chance.  Given the show’s themes of healing and fixing mistakes, it seems like one or both of these characters could receive a full redemption arc.

4.     Exploration of the Dark Side of True Crime

True crime can be one of the most interesting, profound, and socially revealing genres in entertainment today.  Done properly, works of true crime can be humane, insightful, and can provoke positive social changes.  True crime can also be shallow, exploitative, and lurid, and when recklessly crafted, it has the potential to destroy innocent people’s lives.  Only Murders in the Building has been aware of this throughout the series, showing how a mutual affection for the genre can bring people together, and also demonstrating how greedy people exploit tragedies for profit through shock value, and how false accusations can lead to blameless people being thrown into prison.  In season two, it was revealed that one podcast was responsible for a massive miscarriage of justice, but though the reputational fallout for the podcast host was shown in the next season, the fate of the wrongly accused person was not.  Furthermore, the last two seasons have seen mercenary forces try to convince Mabel to monetize her career as a true crime podcaster, and embrace the rather tasteless moniker of “Bloody Mabel.”  So far, the show has just danced around the exploitative aspects of true crime, and seems to be leading in to making them more prominent.  It’ll be interesting to see if they run with this so-far underplayed theme.

5.     Mabel’s Aunt

Mabel’s aunt has been frequently referenced on the series, but has never been seen.  In season one, it was explained that Mabel was allowed to stay in her aunt’s apartment while her aunt was away, in exchange for renovating it.  One side mystery of the first season was how Mabel was able to afford such a massive wardrobe on a freelance artist’s income, though a later season explained that Mabel was borrowing her aunt’s clothes.  By season three, Mabel’s aunt has sold her apartment, without ever making an appearance.  Viewers now have questions– who is this affluent woman who is exactly the same size as her niece?  Where has she been the last couple of years and why did she decide to sell the apartment she’s owned for over a decade?  And why don’t the long-term Arconia residents Charles-Haden and Oliver seem to know anything about her?  At some point, the show will need to explore just who Mabel’s aunt is and what her relationship with her niece is like.

Fans will have to wait and see what happens when season four is released on Hulu at some point in the future.