Populating Will Arnett’s latest comedy was a project in and of itself.

Arnett and his Sony-based Electric Ave. banner had secured the rights to adapt the BAFTA Award-winning BBC Three series Murder in Successville, and now he needed a cadre of celebrity guest stars who’d be willing to improv their way through his spin on the murder mystery. His pitch to prospective talent was simple, if a tad daunting: “We’re basically making Law & Order without a script,” Arnett recalls saying, explaining how he’d be playing the lead detective and they’d be his homicide trainee, and together they’d interview suspects and try to solve a murder.

Having landed the format some four years earlier, Arnett shopped around his version, which counts Krister Johnson (Wet Hot American Summer) as its showrunner, and watched as Netflix stepped up in ways other outlets did not. “They really got what we wanted to do,” says Arnett, who’s done plenty of business with the streaming service already, having made BoJack Horseman, Flaked and the Arrested Development revival there. All six episodes of the procedural crime comedy, as Murderville is being billed, were filmed over the summer and will make their global debut on Feb. 3.

When it came to enlisting those celebrity guest stars, Conan O’Brien was Arnett’s first ask, and a bellwether of sorts for whether industry types would be game. If O’Brien was in, Arnett reasoned, others would be, too. So, he showed the former late night host a sizzle reel of the different-but-similar-in-tone U.K. original, and then he assured O’Brien that it would be no more than two days’ work and, just as important, it would be fun — or at least he hoped it would be fun. To his great relief, O’Brien agreed, and much as Arnett anticipated, “Conan really understood the game of it.” (The completed episode entails Arnett’s character begrudgingly welcoming O’Brien, who plays himself, onto an absurd magic show murder case involving a rival, a former assistant and a moms association.)

Arnett and his team of producers then rounded out their star-studded guest cast with a who’s who of Hollywood funny (or until now, secretly funny): Annie Murphy, Ken Jeong, Kumail Nanjiani, Marshawn Lynch and, yes, Sharon Stone. Each one fronts his or her own episode, starring opposite Arnett, who plays senior detective Terry Seattle, homicide division, in the series. Without a script in hand, the celebrity guest stars are entirely in the dark with regard to what will happen next; and while they’ll improvise their way through the case with Arnett, it’s up to them alone to name the killer at the episode’s conclusion.

“I do think people liked the idea that they could come in, they didn’t have to learn any dialogue and they could be themselves and just go for a ride,” says Arnett, who acknowledges it wasn’t an easy sell. “And I have to give these people credit because it’s freakin’ scary as shit.”

Of course, not everyone involved with the project came into it blind. In fact, there was a staff of eight writers who mapped out every episode, including who would be the victim, the culprit and the suspects each time. There were loose scripts, too, though they featured sizable holes as the guest stars were working entirely off the cuff. “And if it all goes sideways, I’d have to go sideways too,” says Arnett, who’s joined every episode by actors Haneefah Wood (as Chief Rhonda Jenkins-Seattle), Lilan Bowden (medical examiner Amber Kang) and Philip Smithey (detective Darren “Daz” Phillips).

Iain K. Morris (The Inbetweeners) and Brennan Shroff (Southern Belles) shared directing duties on the comedy series, which counts Marc Forman, Jonathan Stern, Peter Principato and Brian Steinberg along with original U.K. star Tom Davis, U.K. creator Andy Brereton and U.K. director James De Frond as exec producers. For Arnett, who’s also an executive producer, the show comes at a particularly busy time. He has a slew of projects already set up or forthcoming across live-action and animated film and TV, to say nothing of his popular Smartless podcast, which Amazon scooped up for a cool eight figures last spring.

Now, as Murderville’s Feb. 3 launch draws closer, Arnett is feeling hopeful, if pragmatic: “I’d love to do more if it works and people respond to it,” he says of his latest series. “And if people kind of shrug and go, ‘Yeah, fine,’ then great, we had a lot of fun.”