The continuing snow flurries were already starting to cover them. ‘I’ll go after him,’ I said.

‘You can’t go on your own, it’s too dangerous.’

Travis looked at the pair of us. ‘You’ve got fifteen minutes. It’ll take us longer to get back down to the landing point anyway.’

I licked my lips; they were already dry and cracked. ‘And if we don’t find him?’

‘Then we’ll take Maggie to the town and come back later.’

I nodded, although that didn’t sound like a brilliant plan. Judging by the state of the weather, things weren’t going to improve any time soon. I was no snow expert but I could tell that the wind was getting stronger. Dangerously so. If this got much worse, the helicopter wouldn’t be able to fly, let alone drop us back here. I caught a look in Travis’s eye before he turned away; he knew it too. If we didn’t find Maggie’s husband and get him to the helicopter soon, we’d be forced to abandon him for the night. And he probably wouldn’t make it if that happened.

‘We’d better get a move on,’ Isla murmured.

‘Fifteen minutes,’ Travis repeated. ‘I mean it. This isn’t the night for silly heroics.’ He looked at me as he said those last words. That wasn’t entirely fair; I’d followed his instructions and commands to the letter over the last four months. Still, I nodded in acknowledgment and Isla and I took off.

The footsteps were close together, suggesting that Maggie’s husband had been moving slowly. That was good, it meant we had a better shot of catching up to him. I followed Isla’s lead, keeping my own steps light and brisk. I counted silently in my head to keep track of the time. Realistically we couldn’t follow his trail for more than eight or nine minutes before we’d have to return.

Time was not our friend and neither was the Coire an t’Sneachda. Even with the crampons I was wearing, my feet struggled to find purchase. Isla wasn’t much better and we slipped and slid our way along. As more of the snow gave way to hard ice, the trail disappeared until we were surrounded by howling winds, lethal rocks and very little else.

‘Which way?’ I shouted to make my voice heard above the growing gale.

Isla looked around. ‘I don’t know. We have to go back. He could be anywhere, he could be miles anyway.’

Bugger it. Moncrieffe or not, we weren’t going to leave him if I could help it. I unzipped the pocket on my thigh. There was always Bob, the genie who’d saddled himself to my side.

Before I could pull out the scimitar – or rather letter opener as it actually was – the wind abruptly changed direction. Unprepared as I was, it yanked me off my feet, flinging me to the ground. I yelled in frustration and tried to pull myself to my feet. As I did, I caught sight of the crevasse to my left.