The Weekend's Viewing: The clues had the semaphored clarity of a creakier kind of crime drama

Mayday, Sun, BBC1 // Being Human, Sun, BBC3

"Why would my husband lie to me about walking the dog?" asked Gail at the beginning of Mayday. Gail was worried about Duke, carrying a lot more about the midriff than a dog should be. And Gail's vet had just suggested that his corpulence simply wasn't consistent with the two-hour daily walk Gail thought he was getting. Gail looked pensive, and she wasn't the only one furrowing her brow in the first episode of BBC1's new thriller. "Alan, where have you been?" asked Fiona, when she found her husband showering in the middle of the day, her confusion only increased when he screamed at her to get out of the bathroom. "Why aren't you at work, Dad?" asked Linus guilelessly, arriving home to find his father struggling to heave a large holdall into a padlocked cupboard. Linus's Dad was a bit testy too: "What you don't know won't hurt you," he snapped when Linus asked what was in the bag.

All of these questions acquire a larger significance when those asking them learn that a local girl has gone missing – the May Queen no less, seen by us at the beginning of Mayday, cycling towards her moment of glory like a personification of Flora. Before long, the camera is closing in on the ticking wheel of an abandoned bike and there's a blurry glimpse of a fugitive figure in the woods. Something has happened to Hattie and the prime suspects have been arranged before us with a symmetrical neatness. Each suspect comes in a banded pack with a fretful and uncertain partner. Each suspect behaves with a perfectly matched degree of shiftiness. And just to round things off, the man who whips up a posse of paedo-hunting locals also has something to worry about. His brother happens to live rough in the local woods, the kind of oddball who'd always be top of a lynch mob's wanted list.

Put that way, it sounds as programmatic as Death in Paradise, which I recently berated for its Cluedo plotting. And you could, theoretically at least, object to Mayday on similar grounds. The clues – unexplained blood on a shirt, cigarette butts in a woodland clearing, that very heavy bag – had the semaphored clarity of a creakier kind of crime drama. I found it tricky to do so in practice though, because Mayday is less about who dun the crime than about what the crime does to the community. A peculiar strain of sylvan gothic began to emerge at the end of the episode, as the search party walked through the woods and one of their number started muttering in a peasanty way about "something ancient" resenting their presence. But the enticing mysteries in the thing remain grounded in ordinary human woes and the knife-edge uncertainties of everyday relationships. Mayday runs for five consecutive nights until Thursday, which means four hours of the coming week are already accounted for.

Sometimes a line just seems to speak to you. "You're trying to make sense of something that fundamentally doesn't make sense," someone said a little way into Being Human, which is about the day-to-day travails of a ghost, a vampire and a werewolf in a flat-share. You're telling me, I thought. I don't watch often enough to fully understand what they were referring to here. It may have been the vampire's ongoing struggle with substance abuse or some folderol about satanic resurrection. I don't much care, frankly, this sort of comic-book cosmology not being one of my things. But every time I do watch, I find myself caring about the characters and relishing Toby Whithouse's writing, which can do funny and heartfelt and wryly offhand with equal facility. It's full of utterly improbable scenarios energised by credible (and recognisable) emotions. The series ends next week, for good apparently, but if you missed it there are ways you can catch up. On telly there is an afterlife.

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