This Only Murders in the Building theory explains literally every loose end and I’m in shock

Are we sure that Howard isn’t an evil cat killer?


Netflix viewers have a long-standing theory about Only Murders in the Building which explains literally every loose end – including why there are so many murders in this one building.

The show’s producer has made mysterious comments about a criminal mastermind – who viewers are nicknaming Moriarty – who has secretly been behind all the murders which have baffled Mabel, Oliver and Charles for four seasons of TV. And not going to lie, when you examine the evidence, it makes a lot of sense.

Warning: this article will obviously contain some serious spoilers for Only Murders in the Building. If you’re not all caught up yet, then read on at your own risk.

There are a hell of a lot of murders for one building

Seriously, why does anyone even bother living there? I’m even less convinced that someone would choose to live in the Arconia than I am that people still go on holiday to the island in Death in Paradise or move to the village in Midsomer Murders. Not only do you have to put up with Selena Gomez spying on you and the near-constant police investigations outside your living room, but you seem to have very high odds of being poisoned, stabbed, shot, or shoved down elevator shafts.

The main characters of Only Murders in the Building in the building solving murders

Surely there can only be murderers left in the building now?
(Image via Disney+)

You could argue that if nobody died, there wouldn’t be a TV show. But that’s a pretty boring answer. Would it not make more sense if all the murders in the building are part of some larger plan, which the heroes will have to stop as the grand finale for the show? It definitely sounds juicier.

This could explain literally every single plot hole

If a secret Moriarty figure is masterminding all the murders, then this would explain who was responsible for some of the loose ends in previous seasons.

Way back in season one, Jan found a creepy note on her door that read, “I’m watching you”. She seemed pretty perturbed by it. At the time, viewers assumed that it had been left there by the person who killed Tim Kono, but since (spoilers!) the killer turned out to be Jan, there was never any explanation for the note. We also never found out who poisoned Oliver’s dog, Winnei.

In season two, the villain Poppy/Becky’s plot hinged on her knowing an awful lot of insider information about the Arconia building and about Bunny’s backstory. Did she have help from a more powerful criminal organisation?

In 2022, TVLine asked the show’s co-creator, John Hoffman, what happened to Winnie the dog. He replied, “We like our loose ends. I don’t mind carrying loose ends from Season 1 to Season 2, from Season 2 to Season 3. There is a long game plan involving some of these clues.”

Jan in Only Murders in the Building

Guys, it’s been four seasons. We can’t keep blaming everything on Jan
(Image via Disney+)

Plus, this theory would be pretty convenient for the writers of Only Murders in the Building. Every time a fan goes “Ooh, you didn’t explain that properly,” the writers can go, “aha, that was definitely the work of that mysterious secret omnipresent overlord. We totally planned that. We didn’t just forget to think of an explanation or anything!”

The producers made mysterious comments about a Moriarty figure

Fyi, Moriarty is the supervillain in the Sherlock Holmes books (and subsequent gazillion films and TV shows and smutty fanfictions). He runs a massive criminal network and subtly masterminds lots of the seemingly unconnected murders which Sherlock solves, until Moriarty dramatically reveals himself as Sherlock’s nemesis. People often use the word “Moriarty” to mean “evil villain who has been secretly behind everything all along mwa ha ha”.

In an Ask Me Anything on Reddit in 2022, a fan asked John Hoffman about some of these loose ends, and he replied, “The poisoning of Winnie and the letter on Jan’s door remain a part of the many mysteries in the Arconia — thinking a little bit like a Moriarty situation if that helps.”

I swear that basically confirms this theory about Only Murders in the Building.

Who is the Moriarty figure, then?

The writers of this show clearly love a bad dad joke and to make puns out of people’s names. In season three, a guy called Cliff shoved someone off a great height. The producer of Oliver’s play who poisoned people was called Donna, kind of like the poison belladonna.

Moriarty from BBC Sherlock

Soz, but every time I type ‘Moriarty’ I just picture Andrew Scott making squeaky noises at Benedict Cumberbatch in BBC’s Sherlock
(Image via BBC iPlayer)

Do any of the characters in Only Murders in the Building have names that link to the Moriarty theory? Absolutely.

The hero’s wholesome neighbour Howard’s surname is Morris. And not going to lie, the evidence is kind of against him.

Before you all wail, “No, not my wholesome sweater-wearing cat-owning king,” just hear me out. Howard is seriously invested in the group’s murder investigations, and is always willing to drop everything to get closer to them. He made a comment in this week’s episode about the cat shelter not letting him adopt pets from them any more – has Howard led more cats to sticky ends than just Barbara and Evelyn?

If Howard was secretly behind all these crimes, then it would explain why the pig Natalie Porkman ran away from Mabel, but seemed happy to sit on a leash with Howard in this episode. Perhaps Howard knew the pig previously. Jonathan, who was Howard’s love interest in the last two seasons, hasn’t appeared or even been mentioned yet in season four. Like, at all. Are we sure he’s alive and well?

Howard is pretty much the only person left in this building who isn’t a main character and hasn’t been murdered. Very sus. Perhaps his wholesome persona is just a ruse to distract people from his machiavellian murder schemes. You never know.

The other character who’s name has a link to Moriarty is Mabel. Her surname is literally “Mora”. Could Mabel be the Moriarty from this Only Murders in the Building theory? Has Mabel somehow been fooling everyone for four seasons by committing the murders she then solves? Does Selena Gomez have the acting ability to bring a plot twist like that into fruition? I’m not convinced.

Selena Gomez as Mabel in Only Murders in the Building

Could criminal activity be financing Mabel’s seemingly unlimited collection of cardigans?
(Image via Disney+)

Another possibility is Mabel’s mysterious aunt, who is mentioned throughout the show but has never appeared. She might also have the surname “Mora”. She did used to live in the Arconia building with all these characters, then she vanished right before Tim Kono was killed at the start of season one. She has bucketloads of cash, since she has a fancy flat in the Arconia and let Mabel live in it rent free, but it’s never been explained where all her money came from. Running some kind of criminal network, perhaps? Maybe she got stressed that Mabel would uncover her secret, and so she sold her flat in an attempt to get Mabel far, far away from the building.

Plus, Aunty Mora does sound quite a lot like Moriarty. It’s the kind of bad pun which the writers of the show seem very into.

Netflix viewers have also theorised the building’s doorman Lester could be an evil mastermind. His surname hasn’t been mentioned, so maybe it’s going to be revealed that he has a family connection to another character, or to the people who designed the Arconia building? Could he be killing off annoying residents so that the building goes bust and he can leave his job? This might be a bit of an extreme reaction when he’s so close to retirement age.

The show could have a messy ending

If there is a Moriarty figure, then they might be revealed at the end of this season as a dramatic cliffhanger ending. Maybe Sazz was killed because Moriarty thought that either she or Charles was getting to close to them?

Be warned: the most famous thing about Moriarty is his ending. Once Sherlock catches onto his crimes, he confronts Moriarty and they tumble off a waterfall in a deeply dramatic and kind of homoerotic way. Both are supposed to be dead, but Sherlock is later revealed to have not died after all (surprise!) so that the author can sell more Sherlock Holmes books. Will Only Murders in the Building have a similarly scary ending at the top of the Arconia building? I certainly hope so.

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Feature image via Disney+