Ah jeez, well, it's … OK then! Ya, it's time for more Minnesota shenanigans as couthy meets callous and naivety bumps up against the nefarious in the third season of the show inspired by the 1996 Coen Brothers movie. Having teamed up Martin Freeman with Billy Bob Thornton for the first series and pitched Kirsten Dunst against Ted Danson in its sort-of prequel, the TV Fargo creator Noah Hawley has gone the extra yard in securing another starry pairing. So, up against Ewan McGregor in this season is, um, well, Ewan McGregor.

If you have anything like a mild phobia of the cheesy-grinned talents of the lad fae Crieff, then it's possible that seeing two of them (occasionally in the same scene) might be stretching things even in Fargo's quirky universe. Ewan 1 plays Emmit Stussy, a successful businessman with wife and kids and a tendency to forget he's wearing slippers just before leaving the house. Ewan 2 is his brother, Ray, a slightly sleazy parole officer who has somewhat underachieved in life but believes he has found love with an ex-con, Nikki Swango (Mary Elizabeth Winstead).

As with the previous two series, daft misunderstandings, bad decisions and misguided ambition leads to a nightmarish web within which its victims only get ever more entangled. Harbouring a long-held belief that he deserves a slice of Emmit's fortune, Ray hires a feckless ne'er-do-well to steal a precious stamp. Naturally enough, he messes up, triggering a chain of unseemly events that drive the narrative into murky depths.

It's all perfectly enjoyable in that peculiar Fargo way where you know that something kooky will inevitably be followed by something monstrous. You can also tick off a few more boxes: likeable cops plunged into relatively rare homicidal dealings; a mysterious and enigmatic baddie (this time it's David Thewlis and some dodgy fake teeth); and, of course, that funny way they all talk. While Ewans 1 and 2 almost slip into Oirish from time to time, it's clear he's done his homework on the accent (ie watched several repeats of series one to copy Martin Freeman's attempt).

While there may be surprises down the line in this year's 'true story', the first few episodes suggest that it won't be a patch on the opening two series and the curse of diminishing returns looks to be biting deep.

Fargo starts on Channel 4, Wed 31 May, 10pm.