Tikaani froze exactly where he was. Beck stared down at the ground in horror, then looked back the way they had come. Their footprints marched side by side across the smooth snow to where they were now.
The too-smooth snow. Beck looked around quickly and his heart sank. He had been looking out for crevasses and missed a danger that was just as great – and more immediate.
Experimentally he poked at the snow by his feet, scraping it away with his stick. The tip hit something hard, but it made a dull, flat noise. It wasn’t scraping against rock.
‘We’re standing on ice,’ he said quietly. ‘There’s a frozen lake under this lot.’
Tikaani looked quickly down at his feet, as if expecting water to well up around them. Beck looked back again. He estimated they hadn’t come that far out. Twenty, twenty-five metres maybe – no more. After that the smooth snow tilted up and a black rock poked up. That would be solid ground.
‘Turn round,’ he said, ‘and walk back over your own footprints . . .’
The ice they had already crossed was strong enough to take their weight. They turned round, and half a minute later were safely back on dry land.
Beck studied the smooth area in front of them with a lot more attention. Only a fool walked across frozen ice if there was a safer way round. The lake was a totally flat stretch of snow for about seventy metres. After that the ground started to slope up again.
He looked from side to side. They were boxed in by rock and by the sheer drop on their left. The lake was the only way forward, but one false step and they could be dunked in freezing water. If that happened, with the wind chill reducing the temperature even further, then hypothermia would follow as surely as night followed day.
‘We don’t have a choice,’ he said reluctantly. ‘We have to go that way . . .’
Beck led the way cautiously down to the edge of the lake and scraped the snow aside again with his stick. The ice beneath was grey and rough.
‘The problem is,’ he said, ‘ice beneath snow is never going to be that thick. The snow insulates it and stops it from freezing further.’
‘So we go straight over,’ said Tikaani. ‘Shortest distance, shortest time.’
‘No, that’s the thinnest ice,’ Beck added. He rapped the grey ice a couple of times. It seemed solid, but it needed to be a good five centimetres thick, he knew, to hold their weight safely. Unfortunately there was no way of telling if it was. ‘The lake will have frozen from the edges in wards, so the ice at the edge will be the oldest and thickest. We have to go round the edge.’
‘You can tell me about how to test food,’ Tikaani said, firmly. ‘Let me tell you about ice. Look.’ He pointed at the edge of the lake, the route Beck intended to take. It was a jumble of loose rocks that had fallen into the water. ‘Rocks sticking up out of the ice mean the ice will be much thinner.’
Beck bit his lip. He could see Tikaani’s point. Unfortunately he also knew that the ice in the middle of the lake could be paper-thin.
‘So we compromise,’ he said.
The boys made their way cautiously onto the lake and around the side, as close to the edge as seemed safe, but not too close to each other – they didn’t want their combined weight putting pressure on any one point.
Tikaani was right – the ice around the rocks was thin. Beck could feel it flex beneath his feet. Halfway round, a large boulder jutted out from the edge, and to stay away from it they had to go out almost to the middle of the lake. With every step, Beck felt the ice creak beneath him. Any moment now he expected it to crack with a sound like a rifle shot and his foot to go through. They were still wearing their snowshoes, which spread the weight of their bodies, but still Beck felt the lake resented them. It knew they were foreign to these mountains; it didn’t want them here.
But the far shore – the rocks and the rising slope that showed solid ground – was getting gradually closer. Beck didn’t get ahead of himself. Even when the shore was only a couple of metres away, he scraped away the snow to check the ice before moving forward. Even if just his foot went through the thin ice at the edge, he could end up with frostbitten toes as ice formed inside his boot.
But finally he was standing on solid ground. He turned and beamed triumphantly at Tikaani. ‘Made it!’
Tikaani smiled back, and took a step towards him.
Suddenly there was a snap that echoed off the rock face, and a splash, and Tikaani vanished as if he had fallen through a trap door.