“Then we’ll have to work by ourselves for the time being,” Longbright told her. “We have the only keys to Bayham Street, and we daren’t admit anyone else to the investigation, so I’m afraid we have to consider ourselves all under house arrest here at the unit until we can get to the truth.”

‘Qanugglir.“ Bryant enunciated so carefully that his dental plate nearly fell out. ”Snowy weather. Kanevcir. First snowfall. Kanut. Crusty snow. Anymanya. A snowstorm. Igadug. A blizzard. Qanüt. Feathery-’

“All right,” May interrupted. “I know you know all of the Inuit words for snow-‘

“Sixty-seven,” said Bryant absently, staring out of the windscreen.

“-but it’s really not very helpful. In fact it’s rather annoying.”

The blizzard showed no sign of abating. The wind had risen to a roar, lifting the snow that had already fallen, swirling it into bleached dunes. The high hedges were buried beneath sculpted white plumes, the sides of the roadway banking into an immense channel, its centre half mile packed with marooned vehicles, anchored in undulating spines of snow. A nearby tree appeared to have been hung with crystal pendants.

Visibility had fallen to around six metres. The vehicle in front of them, a green designer SUV sold on its ability to bounce bounty hunters across rugged terrain but generally owned by middle-class mothers who insisted on driving their fragile darlings to school, had been hastily abandoned, and was subsumed to the top of its wheel arches. The Spar truck behind was starting to look like a Rachel Whiteread sculpture. Looking in his rearview mirror, May could see the driver arguing with his mobile phone. In the last few minutes, one or two passengers had attempted to alight from their vehicles, only to be driven back by the pounding winds.

“How long can this keep up?” asked Bryant, smudging a clear patch on the windscreen with the back of his woolly mitten.

“It’s Dartmoor,” replied his partner. “Normal weather rules don’t apply out here. We have a full tank, but we’ll be in trouble if the engine dies. We can’t stay in this cabin without heat.”

“It’s a marvellous thing, snow,” said Bryant wistfully, appearing not to hear his partner’s concerns. “As much as six feet can fall in a single day, and the volume is ten times that of the equivalent moisture in rainfall. I remember snowfalls in the East End that were so heavy they pulled down the overhead telegraph lines, temperatures so low that sheets of ice slid like guillotine blades from the roofs of cornering taxis.”

In the last few years, Bryant seemed not to concern himself with common fears. He made his way through the world in a state of blithe cheerfulness, leaving a trail of concern and distress behind him. Others fretted for his welfare far more than he did himself, and May had been pressed into service as a professional worrier for everyone’s well-being.

“We cannot stay here,” May reiterated. “People die stranded on Dartmoor, Arthur. It happens almost every winter.”

“Can I light my pipe?” Bryant’s watery blue eyes rolled up at him beseechingly. “It would help me think.”

“No, you cannot. I daren’t open the windows. We’ll freeze to death.”

“A lot of mysterious goings-on on Dartmoor, you know,” said Bryant, digging in the glove compartment. “I was reading about them in my guide book. Hound Tor is haunted by the spirit of a hanged woman, and Okehampton Castle is positively alive with the ghosts of slaughtered nobles. And apparently you should never drive on the B3212 between Postbridge and Two Bridges after dark because a pair of dismembered hairy hands are liable to wrench the steering wheel away from you, sending you careening into a bog. Then there are the Piskies, who are the unbathed children of Eve, exiled by God from the Garden of Eden and sent to Devon, who are said to contain the souls of dead babies, and of course witchcraft is still practised today across Dartmoor, especially near Ringastan. That’s a stone circle excavated in 1903 that was found to have had a false floor in it, filled with coils of human hair.”

“Really, Arthur-‘

“Oh, I know all this seems like old hat, but during the winter solstice of 2005 the police at Moortown found half a dozen sheep with their necks broken and their eyes torn out. Their corpses were arranged in occult patterns. Seven more dead sheep were found arranged in the shape of a heptagram at an ancient pagan sacrificial altar in the shadow of Vixen Tor. Perhaps we’ve been stranded here for a reason.” Bryant rolled his blue eyes meaningfully as the wind moaned around the van.

“This is ridiculous. I’m going to call Janice and see if she can find out what’s happening with the emergency services.” May speed-dialed her number on his mobile and listened.

But Bryant had started having morbid thoughts; he looked out at the ferociously blank landscape and wondered what it would be like to die outside, a painless numbing of the senses accompanied by a shutting out of light, kinder than drowning or even fading in a hospital bed; a sort of suspended animation that held the possibility of being reversed. Snow White and Sleeping Beauty had both slipped into comas, only to be revived by the heat of another human life. He felt something-a faint tremor, a flutter of the heart, a fleeting premonition that beat overhead like a death’s-head moth and vanished with the intrusion of May’s voice.

“Well, what are they suggesting? Of course we’re going to stay put, we don’t have much of a choice. Call me back, then.”

May was staring oddly at the disconnection, as if trying to understand what he had heard. “What’s the matter?” asked Bryant, suddenly concerned about what he had missed.

“I don’t know. She sounded very strange. I think she wanted to tell me-I don’t know, exactly.” He shook the idea from his head. After working for so many years with each other, they had developed certain intuitions that ran against their voiced opinions. “She says the whole of Southwest England has been hit by blizzards. They’re trying to mobilise snow clearers and marine emergency helicopters, but all rescue vehicles have been grounded until the high winds abate. Traffic’s at a standstill everywhere, and there’s worse weather to come. Even the ploughs have been caught out. We have no choice but to stay put here.”

“I wouldn’t worry; it won’t take long to clear the roads, and meanwhile we have food and water and heat. Apart from Alma’s surplus sandwich mountain, there’s a hamper in the back. I was taking it down for the raffle.”

“We should check on the other drivers, warn them to stay in their vehicles, try to make sure they’re all right.” May opened his window and peered out, trying to see, but the blast of icy snow that burst into the van cab forced him to quickly reseal it. He dropped back in his seat, frustrated. “I knew I shouldn’t have left London.”

Several hundred metres back along the road, Madeline and Ryan sat inside their stalled Toyota clinging to each other as the temperature plunged. Snow had soaked a length of stripped cabling and shorted out the vehicle’s ignition. “Don’t worry,” she told her son. “The snowploughs will come and get us. They’re prepared for storms like this.”

“Why doesn’t the heater work without the engine running?” Ryan asked. “It’s not like it uses petrol.”

“No, but it runs on electricity. Here.” She had found a red emergency blanket in the boot of the vehicle, but it wasn’t wide enough to go around both of them, so she tucked it in around her son, hoping he wouldn’t notice that her teeth were chattering. “When we get home I’m making you hot chocolate and buttered crumpets with melted cheese and Marmite, and you can watch all the TV shows I don’t let you watch normally.” Ryan had trusted her and the new man who had come into their lives, only to be betrayed. The least she could do was let him watch some unhealthy television once they were safe and warm again. She hugged him close to her, sensing his fragility through the rough nylon blanket.