If you haven't become hooked on this bizarre impro-celebrity-reality-TV whodunnit yet I seriously doubt if this week’s episode is going to float your boat. But it is a good one. Dermot O’Leary is the showbiz rookie seconded to the Successville constabulary under brutish boss DI Sleet (Tom Davis). I don't think when he quit the X Factor earlier this year it was do this.

And O’Leary has barely got his boots on the desk when there’s a kidnapping to solve. Simon Cowell has been taken hostage so naturally there are plenty of people with a grudge. Cowell wants to knock down Jessie J’s Dojo and the old people’s home run by Miley Cyrus and he also wants to do mean things to Alan Sugar’s sweet shop.

The former X Factor presenter and Sleet are quickly on the case, but it’s Cariad Lloyd who steals the show as Cyrus. What with her recent successful appearance on Have I Got News For You Lloyd is finally moving up the comedy rankings. Marie Lawrence is also good, channelling a whiff of Twin Peaks as spooky Lana Del Ray and Ricky Grover exudes his usual scary menace playing Alan Sugar with a hint of Ray Winstone.

As for O’Leary, it’s hard to shake off his Mr Nice Guy image even when he smashes up Sugar’s sweet shop. You feel he wants to hug the suspects rather than put cuffs on them. He’s certainly learnt that the art of improv is never blocking a suggestion though, as he gamely attempts an ad libbed lecture on ships in bottles at the old people’s home (“shits in bottles?” asks one of the deaf inmates) and does a spot of kung fu when confronted by Jessie J. He’s funny, but I don’t think Hollywood is going to come calling just yet. 

Lots of good gags, some genuine surprises and a rather mean quip at the expense of Russell Kane. While I imagine there were some retakes this still retains a loose, spontaneous feel, albeit the kind that some critics might call amateurish. It’s an utterly ridiculous concept and an utterly ridiculous show, yet it somehow works.

Murder In Successville, BBC3, Wednesday, 10pm.