The reference is deliberate, as it was over British comedy that Clement and Waititi first bonded at university: Blackadder, The Comic Strip, Fawlty Towers. “I could hear rats running around in the loft. “The flat I lived in with Bret was the filthiest ever, man,” says Clement. It’s like a bizarre university dorm, in part inspired by Clement, McKenzie and Waititi’s own student experiences. Shacked up together to hide from the sunlight, they get on each other’s wicks, as you would if you lived with three other men for eternity. Rather than make the most of their unending time, these bored bloodsuckers are stuck in complacent ruts.

Clement is Vladislav, an 862-year-old ladykiller, Waititi is Viago, a 379-year-old people-pleaser, and they’re joined by Petyr (Ben Fransham), an 8,000-year-old Nosferatu-like misanthropist and Deacon (Jonathan Brugh), an ex-Nazi vampire who, at just 183 years of age, is a bit gauche.

Part Spinal Tap, part The Only Way Is Transylvania, What We Do… concerns the lives of four vampires cohabiting in an appropriately gothic house, arguing over rotting corpses and bickering over dirty dishes. It turns out though that Clement has another long-term comic partner, Taika Waititi, with whom he’s in London to promote the film they wrote and directed together: the very funny and, yes, dry as hell mockumentary What We Do in the Shadows. McKenzie has opted for the musical side of things, writing the songs for two Muppet movies, while Clement has become the arch lord of deadpan, appearing as delusional despots in films such as Gentlemen Broncos and Men In Black 3 and contributing his unmistakable tones to animations Despicable Me and Rio. Since the last episode of the Conchords’ two seasons aired in 2009, they’ve performed a few live shows but have been non-committal about a full-blown reunion, instead pursuing separate film careers. Concerning a hapless band attempting to find success with both music and women, it was Perrier-nominated at Edinburgh, found a home on Radio 2, then crossed the Atlantic to settle very nicely on HBO. The world first met him via the Conchords, the show of the group he formed with Bret McKenzie at university in Wellington in the late 1990s. “No, it’s probably best you didn’t,” he says sitting back down, with a dryness we’ve come to expect from the more sardonic half of Flight of the Conchords. He hasn’t done it since that first time, he says (for good reason). Inside, a few minutes later, remembering the first thing he did at his university’s drama club, he’s robot-dancing around the room. When I find him at 10am, he’s leaping over the fountains of London’s Somerset House courtyard, grinning like a buffoon for his mate’s phone camera. Jemaine Clement is being Jemaine Clement.

Return of the shadow