When Joe Gilgun's on screen it's difficult to take your eyes off him - so mesmerising is he as split-personality superhero Rudy. Tonight there's three of him cussing and wise-cracking: his evil alter ego has come back to terrorise the other two (only slightly evil) Rudys. Even by the show's demented standards it's beyond belief and yet Gilgun manages to make it completely convincing.

Jess, meanwhile, is falling for the barman, Finn's step-mum gets a little too close and Curtis has a run-in with the new probation officer.

After a third, violent and incredibly sinister version of Rudy is released from prison, two things become quickly apparent: he has a disturbing obsession with Jess, and he even terrifies his other two (already pretty unsavoury) doppelgängers. With Finn trying to ward off advances from his horny step-mum and Curtis attempting to prove his bad boy credentials to trainee probation worker Lola, this certainly shows a darker side of Misfits. The new Rudy, played with disturbing and brilliant intensity by Joe Gilgun, exudes a simmering menace throughout, Jess's vulnerability gives her some much-needed depth and Finn comes off as both sympathetic and a total idiot. But Curtis and Alex feel slightly superfluous, the latter's brief appearance suggesting that the big 'reveal' regarding his fear of women is set to be a frustrating slow-burner.

Last week we were left wondering why new boy Finn has a woman gagged and bound to his bed. Naturally, it has to do with the occasionally wonderful but mostly weird superpowers with which all the Misfits are endowed - this one is possibly the most inventive yet.

Meanwhile, ex-EastEnder Shaun Dooley growls, gnashes his teeth and generally has a whale of a time as the terrifying new probation officer. But it's still Joe Gilgun as Rudy who gets the lewdest, crudest gags and all the best lines. This week Rudy is surprised to discover he has principles.

Misfits: Series 4 Episode 2 review

Love him or loathe him (and we love him), Rudy is without a doubt the character that Misfits' writers have the best grasp of, which is why Joe Gilgun consistently and brilliantly steals focus in an episode that's meant to explore newcomer Finn (Nathan McMullen).

The superheroes are back, although devotees will miss Alisha and Simon who departed at the end of the last series. Newcomers are likely to be utterly befuddled - as are the new Misfits: doe-eyed, moody Jess and motor-mouthed Finn. They turn up for their first day of community service clad in the obligatory orange jumpsuits and in possession of the requisite superpowers. Posing as their probation officer, fellow young offender Rudy (the fabulously frenzied Joe Gilgun) soon drags them into the deep end. Prepare for power tools, mind-bending flashbacks and fruity language.

Wholesale cast overhauls can be difficult at the best of times, and this opener to series four suggests that Misfits hasn't recovered its poise yet after the departures of Kelly, Simon and Alisha. Curtis and Rudy remain, along with honorary Misfit Seth, to fight over a mysterious suitcase brought into their midst by a delirious lunatic. Timing their arrival less than perfectly are new recruits Jess (Karla Crome from Hit & Miss) and Finn (newcomer Nathan McMullen), both sullenly drawn into the intrigue as alliances are formed and then severed. It has its moments (largely thanks to Joe Gilgun's Rudy), but mostly amounts to a slightly lacklustre take on the failed-heist fallout, with the excellent Crome something of a spare part for now. Surely there's too much talent on- and off-screen for Misfits to lose its way entirely, but this is a problematic reinvention so far.

It's a testing time for the super-powered community-service caper as the fourth series kicks off. It's survived the departure of a key player before, when subbing Joe Gilgun for Robert Sheehan proved a masterstroke. But with no less than three of the original cast, including Iwan Rheon's Simon, gone this time round, can it still cast its spell? With Karla Crome (so good in BBC2's Murder) among the newcomers, it's got a fighting chance.

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