Crikey! Even with my head well and truly logged into the charmingly barmy world of Misfits, officially the nuttiest show since Green Wing, the twist in this second episode came as a totally flabbergasting shock.

As if it wasn't hilarious enough to be watching Nathan getting caught up in a completely ridiculous, extended and very unsexy sex scene with his crush whom he met while helping out at the OAP centre tea dance, we discover, during said sex, that gorgeous young Ruth is, in fact, 82-year-old Ruth, who had been charged with the ability to de-age herself.

The scene was built so well that it was all entirely plausible right up until the stomach-churning reality kicked in: they're in Ruth's grandmother's house, but she's out, they make out on the stairlift up to the bedroom, and Nathan gets a bit overexcited, and then they try it a second time and he knocks the panic button by the bed, triggering off a lot of flapping, which triggers... young lady to old lady morphing! We immediately shared in Nathan's ample distress.

This ballsy, unabashed plot twist helped in extending the core idea of the storm causing sudden superpowers in people outside our immediate protagonists. It's clear, now, that this is a much wider phenomenon.

Poor Nathan, who was deeply traumatised by all the happenings in this episode, also discovered that his mother's ... the man who lives with his mother ... (by the end of the episode he'd started accepting him as her boyfriend) is actually a shapeshifter. Jeremy had been seen by Nathan on two occasions, fully naked and scrabbling about like an animal. We learnt, once Nathan had succeeded in confronting Jeremy, slipping in a punch for good measure, that, for Jeremy since the storm, "sometimes it's like I'm a dog".

The dynamic between Nathan, his mum and Jeremy is touching and funny, and there was good progress made here. Though Nathan's still lying to his mum about having a flat and being able to live independently - he's actually kipping on the community centre floor and living off pizza and booze - he's now doing so to help her have a life of her own, thanks to some sage advice from old lady Ruth. He left Jeremy with a final flourishing word and a cheeky Nathan wink: "If you ever hurt her, I'll take you to the vets and have you put down."

In non-Nathan plots this week - there aren't many! He's still headlining, and hurrah for that. Alisha's not yet worked out a way to make something positive out of her almighty seduction powers, and found herself wildly turning on a helpless police officer (a cameo for the very funny Nicholas Burns of Nathan Barley fame) during a meeting about her ASBO terms.

Kelly hasn't got much joy from her mind reading yet, apart from hearing Nathan thinking horrified thoughts about sleeping with a pensioner, which she duly relayed to the group for their amusement.

Simon is getting weirder and weirder, and is having an online relationship with ‘shygirl18', whom we haven't met yet, but who is bound to get him in trouble.

Our misfits are bonded, for better or worse, by their knowledge of having killed their probation worker. They can't oust weird Simon because they can't afford to turn against one another, particularly now that they've started getting ‘I know what you did' notes stuck inside their lockers from someone. The tension about the probation worker is just enough to keep our guys on their toes, without engulfing what is really a story about how they're going to cope with powers as they go about their community service and their normal lives.

And Nathan still hasn't discovered his own super power! What a brilliant twist in itself, that he, and we, are having to wait to find out what it is. It must be that the power will show itself up when Nathan really needs it.

It doesn't matter a jot at the moment. He's still, by far, the most fabulous character and Sheehan the most compelling actor in the pack - seriously, even the way he smokes is witty.

But he can do serious, too. His reaction on visiting Ruth and finding her peacefully dead, clutching an album of photographs of herself in her youth, was handled beautifully and amounted to a thoroughly tender moment, right down to his little affectionate mutter under his breath of "You tart".

I think that blend of dry comedy and pathos, kept in perfect balance across this week's episode, is exactly why Misfits is working so well.

Read our review of the opening episode here.

Misfits airs in the UK on Thursdays at 10pm on E4 and 11pm on E4+1, with repeat showings the following Wednesday at 11 and 12pm.