Judging from its website, Hebden Bridge’s tourist office considers the fact that BBC1’s Happy Valley is filmed in the town something of a selling point. Personally, I can’t see why. (Perhaps points of especial tourist interest might include the cellar where Sergeant Catherine Cawood was almost battered to death, or the caravan site where drug dealers fed heroin to the teenage girl they’d kidnapped and raped.) And now that it’s back for a second series, viewers of Sally Wainwright’s Bafta-winning drama are still unlikely to confuse Hebden Bridge with, say, Chipping Norton.

In Tuesday’s opening scene Catherine (Sarah Lancashire) filled in her sister on the events of her day. ‘Three lads out of their head on acid,’ she chuckled wearily, stole a sheep from a local farm, and, after it was mauled by the dogs on the housing estate, she had to finish it off with a rock to the head.

But naturally the programme didn’t remain that light-hearted for long. Soon afterwards, Catherine discovered the decomposing corpse of a woman who’d been sexually abused with a broken bottle and then strangled. Not only that, but the dead woman was Lynn Dewhurst, mother of Tommy Lee Royce, series one’s psycho-in-chief — who, in a characteristic Happy Valley twist, is also the father of Catherine’s grandson Ryan, having raped her daughter, who committed suicide shortly after the birth. As a result, Catherine’s earlier threats about what she’d do if Lynn didn’t keep away from Ryan briefly made her a suspect — until it became clear there’s a serial killer about.

For some drama series, this might be enough to be going on with for now. Happy Valley, though, has never been a show to leave fans of the crunching storyline feeling short-changed. One of the investigating officers is being blackmailed by his former mistress with pictures of him passed out in women’s underwear that she created after drugging him. And then there’s Tommy, played by James Norton, for whom the first series was his big break before, by common tabloid consent, he went on to put the phwoar into the BBC’s Phwoar and Peace. Although he’s now in prison, Tommy still has ways of spying on Ryan and deeply unsettling the rest of us. Put like this, Happy Valley might sound wildly excessive, even silly.

Yet, once again, the more lurid moments are constantly offset — and sometimes combined — with some neat comedy and plenty of deft humanising touches. The whole thing’s also written and performed with such utter conviction that series two already feels in with a definite chance of matching its predecessor as an example of a full-strength, cranked-up-to-11 drama that still retains genuine heart: a genre that Brits seem particularly good at these days — especially, you can’t help noticing, if they’re Northern.

Meanwhile, the week’s other big TV comeback wasn’t an understated affair either. Indeed, in the new series of The X-Files (Channel 5, Monday) Mulder and Scully (David Duchovny and Gillian Anderson) are facing ‘perhaps the most evil conspiracy the world has ever known’. Again.

Returning after 14 years, the show didn’t bother finding a way of integrating the required recap with the rest of the action. Instead, Mulder’s opening voiceover comprised a brief autobiography, a quick reminder, in the manner of Monty Python’s Summarise Proust competition, of the key events of the previous 202 episodes, and a little refresher on the basic plot. This, you may remember, is that aliens first arrived on earth thousands of years ago, have been reliably spotted many times over the centuries and since the Roswell incident of 1947 have been working with sections of the American government to colonise the earth, pausing only to abduct and impregnate the occasional human female.

Except, it now turns out, things might not be quite so simple after all. The conspiracy theory that Mulder has espoused all these years might itself be the product of a conspiracy. Aliens did of course come to Roswell in 1947 (the programme wasn’t so nuts as to deny that) but it seems they had no intention of colonising. Rather, the H-Bombs exploding at the time acted ‘as transducers, drawing alien life forms through wormholes’. Fortunately, the aliens were happy to come so they could save us from ourselves. Less fortunately, the US military killed them, nicked their technology and have been framing them for abductions ever since, with the aim of passing off their own plans for world domination as an invasion from space.

Put like this, the new X-Files might sound wildly excessive, even silly. But in this case, that’s because it is. At one point, an ally of Mulder’s warned of the takeover of America by ‘a well-oiled, well-armed group of elites that will cull, kill and subjugate’ — before adding darkly, ‘It’ll probably start on a Friday.’