Last night's viewing - Utopia, Channel 4; Yes, Prime Minister, Gold

Utopia is nasty. Then again, Utopia wants to be nasty, so you can take that verdict both as a fair warning and as a recognition that it has achieved its ambitions. Utopia is distinctly comic book, too. But again, given that the plot of Dennis Kelly's conspiracy thriller centres on a fabled graphic novel that is rumoured to have darkly predictive powers, comic book is precisely what it wants to be. Marc Munden's direction, full of tightly drawn framing and double-page wide shots, takes its cues from a comic's way of presenting a story. And, as is often the case in these things, the story takes pleasure in bringing together the shadowy world of dark forces with the supremely ordinary world of the kind of people who hang around fan fairs and can tell you the serial number of every issue of Superman.

It begins as it means to go on, with the arrival of two taciturn men in a graphic-novel store. They murder everyone present, pausing only now and then to ask, "Where is Jessica Hyde?", a question none of their victims appear to understand. The 10-year-old boy detected cowering under a display rack isn't spared, which is a way of letting us know we won't be either. But the killers, reassuringly, aren't the steely men in black overcoats who generally do this kind of thing in comic books. In fact, they're borderline gormless, though that doesn't in any way undermine their menace. And that hint that stock components will be given a little twist proves reliable. A little later, there's one of those rush-of-lust knee-tremblers that popular thrillers love, only in this one everything goes awkwardly awry, as it most likely would in life.

The killers are trying to track down Utopia 2, also the object of fervent speculation on a specialist chatroom. And when five fans agree to meet up to discuss the thrilling rumour that one of them has tracked down a copy, they become targets for the assassins as well. Alongside their attempts to stay ahead of their pursuers runs a parallel storyline about a blackmailed civil servant, forced to put in a large order for flu vaccine with a Russian pharmaceutical company. And behind both stories sit "They", as yet unrevealed but with the power to tinker with DNA records and track mobile calls. Rather neatly, one of them, Wilson, supplies both comic relief and a shocking confirmation that paranoids can sometimes be realists. "I don't drink tea," says Wilson at one point. "Caffeine was invented by the CIA." But then the killers catch up and Wilson is subjected to torture so extended and so horrible that you may begin to wonder why it's necessary at all.

I'm not entirely convinced it is, but as nasty as Utopia can get, you never get the feeling that it's just toying with interchangeable puppets. A dystopian fantasy has been populated with relatively real characters and genre terrors mixed with familiar human ones – that the boy you like might be interested in someone else, or that your alcoholic mum might one day not come out of her stupor. And all of it is delivered with great visual style. Get out the glassine envelopes and collect the whole set.

The revived Yes, Prime Minister, returning after a 24-year absence, at least came in on the perfect political cue. "Dealing with Europe isn't about achieving success," David Haig's exasperated PM tells the head of his Policy Unit, "it's about concealing failure." But that kind of timing isn't what comedy is about and in two ways this was a beat or two off. For one thing, you just can't pretend that The Thick of It never happened, as this seemed to do in featuring a scene of political advisers wincing as their boss flounders through an interview. For another, Henry Goodman can't quite expunge the memory of Nigel Hawthorne's silky perfection. Further consultation required.