It’s likely 2015 will be remembered as a year of serious upheaval in TV comedy—Jon Stewart retiring, Letterman handing his late-night spot to Stephen Colbert, and the beloved sitcom Parks & Recreation coming to an end. But the departure of Key & Peele after five seasons on Comedy Central deserves to be remembered as the biggest loss of them all, because it was the only example of a show ending when it still had so much originality and energy left. To be sure, the creators and stars Jordan Peele and Keegan-Michael Key had good reasons to call it quits: They could make the rare, dignified decision to end the show on a high note, and both are embarking on big film projects. But that didn’t make Thursday night’s series finale any less sad, as the episode demonstrated how much the show had grown and evolved into a comedy classic since its start in 2012.

Sketch shows are always tough to bring full circle: Since there’s no plot, there’s no specific beginning to reference to offer a feeling of closure. But Key & Peele’s finale managed to do so anyway. Season five’s interludes between sketches featured Key and Peele chatting as they drove together down a desert road. The final episode included a nod to the show’s first-ever sketch—in which two men retreated to increasingly implausible locations to say the word “bitch” without their girlfriends hearing—by allowing the pair to finally say their forbidden word without fear of reprimand. It was a small, but telling example of how cleverly the show played with its own formatting over the years to the very end.

Even better was the finale’s central sketch, “Negrotown,” a full-blast, Busby Berkeley musical number on a giant Hollywood soundstage, with Peele (who has a wonderful singing voice) belting out the pleasures of a city populated only with black people. By the end, it all turned out to be the sad hallucination of a man wrongfully arrested by the cops after simply talking back to an officer. Key & Peele has always paid outstanding attention to detail, from the costuming and wigs of the many characters its two central actors took on, to the cinematic approach to shooting its sketches, which feel a universe apart from their roots in Saturday Night Live, Monty Python, and others. “Negrotown” was an epic culmination of that rigorous sensibility, but it retained the trademark grimness of many Key & Peele sketches.

Often, the show’s cinematic ambitiousness would amplify the sketches’ dark subject matter. “Negrotown” was crushing to watch because it was unafraid to go over the top to make a bleak point. The show’s most memorable sequences often had a haunting air to them, like the ode to continental breakfast. Or they were luridly, violently funny, like the two church ladies doing profane battle with Satan himself. Or sometimes the joke was simply how deeply depressing the material was, like this behind-the-scenes look at the sitcom Family Matters.

All of which points to perhaps the biggest vacuum Key & Peele leaves behind. Besides being one of the best comedies on television to deal with race, it also excelled at finding laughter in otherwise seemingly humorless topics—slavery, suicide, terrorist attacks. Moving forward, Comedy Central is cultivating a broad range of voices as many of its top personalities head elsewhere; at the very least, comedy fans can look forward to seeing Trevor Noah and Hannibal Buress’s new shows find their rhythm. But as the last three years have shown—and as Thursday’s finale made painfully clear—the originality, charm, intensity, and fearlessness of Key & Peele will be impossible to replace.