He pushed on. The temperature was dropping, the snow becoming icier and more slippery. Several times he stumbled and fell. Half an hour passed. An hour. Maybe longer. He tripped. His left ankle twisted and he called out in pain. His voice echoed. He hoped nobody had heard.

He winced. He wasn’t sure he could get up. All the energy seemed to have drained from his body. He was tired. Sleepy, almost. He wondered if he should just lie down for a while. Get some kip. Carry on when he had more energy …

No! A voice rang in his head. What had he told Sami? If you start to get confused, or sleepy, or your movements are slow, that’s hypothermia. If that happens, you have to use the beacon.

He shook himself awake. The beacon was there, hanging round his neck. All he had to do was press the button and someone would come to rescue him. Slowly his hands crept towards it.

Then they stopped. He pictured Hector standing over him with an ‘I told you so’ look on his face.

Max grimaced at the thought. He would have to be in a far worse position for that to happen. He pushed himself painfully to his feet.

He blinked heavily. Something had just occurred to him. When he had fallen and shouted out, his voice had echoed.

But what had it echoed against?

He shouted out again. ‘Hello! Hello!’

His voice returned to him a fraction of a second later. The echo seemed to come from his right. He staggered in that direction. Suddenly, through the blizzard, a high vertical wall of rock came into view.

Max grinned. All his sluggishness had fallen away. He checked the map again and pinpointed the two walls of rock that marked his ascent. He was on the right track.

He headed uphill. The cold air was sharp against his face, but he had renewed energy as he battled through the blizzard. Ten minutes passed. Twenty minutes. The steep slope levelled off. Max stood to catch his breath. He had been so intent on climbing that he hadn’t realised that it wasn’t snowing so hard up here. As he looked around, he could see swirls of cloud. His surroundings appeared for a few seconds, then disappeared again, enshrouded in mist. It cleared again – and Max saw that he was not alone.

The ridge line that he expected the others would be following was about fifty metres to his right. There was nobody on it. Max reckoned he’d made the right call: that route was too slow. But between him and the ridge line, cutting up through another snow-filled gulley, was a figure striding up the hill. Max only glimpsed the figure for a few seconds but he was certain that he recognised the form and the gait.