Tonight's viewing: Operation Iceberg, BBC2 Horror Europa with Mark Gatiss, BBC4 "If you think icebergs are nothing more than floating chunks of ice, prepare to think again!" warned the voiceover at the beginning of Operation Iceberg, the first of a two-part natural history series about the Arctic. If you thought that, it occurred to me, you wouldn't be very likely to be watching a programme called Operation Iceberg in the first place. A contemptuous refusal to take icebergs seriously would surely rule you out as part of the core audience. Perhaps they were just hoping to seduce confirmed iceberg belittlers who'd stumbled on the film while channel surfing ("Oh, bloody hell. We've hit a floating chunk of ice"). Or perhaps it was just a reflexive twitch of the nervous oversell that accompanies so many programmes these days, and which at first led me to be a bit sceptical about the claim that lives had been risked to bring us these pictures. As it turned out that wasn't overstatement at all. Chris Packham was fronting up this account of an expedition to the Store Glacier in Greenland, but the team of scientists he was accompanying were doing most of the risky stuff (unless you count feeding expedition pasta to a curious arctic fox). And it really was risky, involving the kind of brinkmanship that had bits of your body involuntarily clenching in dread. A scientist dropped on to the very lip of a calving glacier to install a GPS tracker, and then started drilling into it with a giant augur. You imagined a hairline crack snaking out and several thousand tons of ice dropping out from beneath his feet. Two other expedition members went diving in a glacier lake, apparently sanguine about the possibility that it might at any moment drain out through a vertical sinkhole to the glacier's base (one diver even attempted to wedge himself into the likeliest candidate for the inevitable outrush). And if, like me, you wondered whether the voiceover was talking up the hazards of sailing in front of the glacier then, like me, you will have been incontrovertibly put right by the event they caught on camera just as they were packing up - the calving of a massive iceberg that churned the sea where the expedition yacht had been into a spectacular and unsurvivable maelstrom. "You know how we're all kids at heart and really love a good car crash?" said one of the cameraman grinning from ear to ear, "Well that was a really good car crash." He seemed unpreturbed by the fact that if it had happened a few days earlier he'd have been in it. The best line in Horror Europa, Mark Gatiss's celebration of European horror films, came as he was filling us in on Daughters of Darkness. "The countess and her friend are, of course, lesbian vampires," he said offhandedly. That "of course" rather neatly pins down a problem with the whole horror genre, which is that it can be very predictable in its unconventionality. Or at least it can when it hits the commercial, exploitation end of the horror market, because, as Gatiss reminded you here, some classic horror movies have been among the most experimental and influential films made. Gatiss's presentation comes with an undercurrent of anxiety, because you can never quite shake the feeling that he's playing someone presenting a horror buff, and that at some point the perfect pastiche of a BBC4 cineaste documentary will give way to horror itself. The effect was amplified here by John Das's direction, which had Gatiss doing his pieces to camera in the locations you'd just seen in the clips, sometimes accompanied by spectral doppelgängers or threatening figures. I could have handled a slightly less reverential tone myself, given how schlocky quite a few of these films are. But it offered a very crisp introduction for beginners and lots of treats for aficionados too, including interviews with Dario Argento, Harry Kümel and Guillermo del Toro.