So often when a TV show takes a big risk or makes a big choice, it’s seen as a grab for ratings. And yet, when it comes to season four of The Last Man on Earth, some of the most extreme storytelling decisions seem to be simply motivated by…creativity?

The Fox comedy developed its interesting premise throughout the first season (these are the last people left alive after a major virus tore through the country/world), found ways to expand its universe in season two, cemented itself as a truly funny, emotional and adventurous show in season three, and explored some deeply dark, crazy, and even disturbing moments while retaining the humor and heart of the show in season four. And the real magic trick here is that the show has only gotten better, smarter, and more specific along the way. Hey, even Justin Bieber has expressed his love for the show!

The latest episode, “Karl,” not only established the show was one of the most serialized half-hour comedies on TV today, but also left viewers nothing short of shook. If you decided to pop in and check out that episode having no previous knowledge of what The Last Man on Earth is, you’d be confused as hell (albeit quite entertained) and probably run screaming from your screen.

“Karl” introduced us to Fred Armisen’s Karl, a weird enough guy who is revealed to also be crazy and crazy dangerous considering he’s got a leftover decapitated human head hanging out in his freezer next to the ice cream. After an awkward date with yet another guest star, Leighton Meester putting those comedy chops to good use after the cancellation of last year’s Making History, Karl also goes on to murder a sweet Martin Short, a mere seconds after viewers even had the chance to recognize him. That’s a lot of entertainment in a short amount of time! But that’s what this show has excelled in presenting as it’s ticked along. Plus, with all the action, cameos, and even the subtler, sweeter moments, The Last Man on Earth has nearly declared itself appointment viewing: you’re gonna want to watch when it airs on Sunday night if you want to avoid spoilers worth chatting about the next morning.

While the entire episode focused on Karl, including his Mexican adventures and eventual stint in prison, it’s not until the final moment that he meets our old pals Todd (Mel Rodriguez) and Tandy (Will Forte), and the poor souls have no idea they’ve just encountered a cannibal. Well, they met him at a prison, so they might have some indication.

From the frozen heads to the grisly Martin Short murder, it was an episode that proved to be a bit more violent and unsettling than we’re used to seeing. Yes, even from the show that is known for killing it’s super famous guest stars (Will Ferrell, Jon Hamm, and Jack Black) nearly as soon as they step on screen in each season’s premiere episode. But somehow the disturbing moments here feel necessary and useful. The shift could be felt in season three, as Lewis’ (Kenneth Choi) untimely demise and Gail’s (Mary Steenburgen) elevator troubles were both shocking and anxiety-inducing. However, they ultimately heightened the emotional stakes in a way that only kept things feeling fresh and unsure in an exciting way.

Just as The Last Man on Earth has previously dedicated full episodes to other survivors, including season two’s Jason Sudeikis-led episode from space to the sea, and Kristen Wiig’s season three bunker shenanigans, for season four it was Armisen who continued the tradition of designating Forte’s past SNL pals with their own edgy standalone episode. It’s these episodes that carry the duty and responsibility of resetting where the season is heading while also throwing our favorite group of survivors into a tailspin.

With so few functioning humans still left on Earth, the amount of adventures this group has gotten themselves into is really something. The premise isn’t an easy one to work with, but somehow The Last Man on Earth writers have figured out a way to expand their world without breaking the rules they’ve set in place, or eliciting skepticism or anything close to boredom from invested viewers. This season alone has delved into topics such as feminism, former cartel leaders, and parenting. Bit of a variety there, wouldn’t you say? But, just like the extreme measures they’re taking when it comes to potentially gruesome moments, it all seems to make sense. Yes, even that time newborns were compared to fast food. From a storytelling perspective, the risks are paying off. And really, how many other shows on Earth can say the same?

Where to watch The Last Man on Earth