They each had a length of home-made rope in their rucksacks. Beck tied the two ends together and tugged hard. The knot held.
‘In case I run away?’ Tikaani asked.
‘The good news,’ Beck explained, ‘is this ice won’t break beneath you like the lake did. The bad news – there’ll be cracks in it. It weighs thousands of tons and there are huge stresses on it, so it develops crevasses, like I told you earlier. They may be covered up, so you have to look out for snow that dips a little and looks a bit darker. You fall into one of them, and it’s a deep one, you ain’t ever getting out.’
‘So if you fall,’ Tikaani said, fingering the rope thoughtfully, ‘it’s up to me to catch you and pull you up?’
‘Yeah, if you could . . .’ Beck made it sound like some small favour. ‘And I guess I’ll do the same for you.’
They walked a bit further up on firm land before stepping onto the ice. The glacier curved at the point where they were approaching it, and Beck knew that the outside bend is often where crevasses are found. It is the area where the strains on the ice are at a maximum.
‘Stay a few metres behind me,’ Beck instructed. ‘Don’t let the rope drag on the ground. Walk in my footprints, and every step you take’ – he jabbed, hard, at the ice in front of him with his stick – ‘test it first.’
‘Even if you’ve just walked on it?’ Tikaani asked.
‘Even if. For all you know, I’ve just weakened it so it’ll collapse under you!’
‘Well, sure.’ Tikaani shrugged. ‘What else are friends for?’
They moved onto the ice, slowly at first, then with increasing confidence. Fortunately it was still covered with a layer of powdered snow that crunched and compressed beneath their feet. Later in the year, when all the snow had gone, they would have been walking on bare ice, slithering and sliding everywhere.
Beck headed for the middle of the glacier before turning uphill again. Crevasses were also common at a glacier’s edge, where it dragged against the hard rock of the mountain. The middle should be flowing more smoothly.
They came to their first crevasse about twenty minutes later, a few hundred metres further up. After all their precautions, it wasn’t hidden and it didn’t swallow either of them up without warning. But it was still dangerous. It stretched right across the valley, from edge to edge. A gaping crack in the ice, about thirty metres deep and three across. Sometimes there was a thin span of ice across it; mostly it was just open to the sky. Beck guessed that the valley floor pushed up beneath the glacier at this point. It had put a stress on the ice that made it open up here.
‘You know,’ Tikaani said thoughtfully, ‘I bet I could jump that. We throw our rucksacks over first, then we remove our snowshoes and take a run-up . . .’
Beck shook his head. ‘You don’t know how solid the edges are. The far side might just crumble beneath you. We need an ice bridge.’
Tikaani looked at him. ‘And I bet you know an ancient Anak method for making one of them?’
Beck smiled and shook his head again. ‘Nature makes ’em; we just use ’em. This way.’
They walked slowly along the edge of the crevasse to the nearest of the bridges. It was about three metres long, from one side of the crevasse to the other, and about a metre wide. It sagged in the middle, which didn’t fill Beck with confidence. He poked it with his stick. Immediately it split and tumbled into the crack.
‘Not that one,’ he said as the fragments hit the bottom and shattered into a million pieces.
They tried several more of the bridges. Not all of them crumbled, but . . .
Some of them were too narrow. Some Beck just didn’t like the look of. He wanted good thick ice – several centimetres of it at least – that didn’t sag. He wanted it to form an arch with the ends thicker than the middle. That way it would give itself extra strength.
None of them were exactly perfect. But time was ticking away – time to save Uncle Al and, more immediately, to get over the mountains.
‘After you,’ said Tikaani politely, not taking his eyes off the thin bridge that was the best contender. It was thicker than the rest and it didn’t shift when Beck poked it.
‘Yup,’ Beck agreed.
Tikaani peered into the depths. ‘If you fall, I’m really not sure I can hold you . . .’
‘Nor am I,’ Beck agreed again, to Tikaani’s obvious surprise. ‘So take your pack off . . .’
The layer of snow on top of the glacier was a couple of feet deep. The boys scooped out a hole and buried Tikaani’s rucksack. They then tied the rope to it. Now the rope stuck out of a pile of churned-up snow. The end was wrapped round Beck’s waist.
‘It’ll never hold,’ Tikaani said sceptically a few minutes later. ‘It’ll never hold!’
‘You reckon?’ he said with a grin. He hadn’t believed it himself when he’d first seen this done. He passed the rope to Tikaani. ‘Back off a couple of metres and give it a tug. Go on.’
Frowning with doubt, Tikaani took the rope and pulled. And pulled again. The buried rucksack stayed exactly where it was. He looked up at Beck, baffled.
‘Snow’s like that,’ Beck told him. ‘It’s loose, it’s fragile, it crumbles easily – but if you apply force to it, it can jam solid. You could pull the sack straight up, but you can’t drag it through the snow.’
Tikaani looked from the buried pack, to the rope, to the crevasse. ‘I still . . . can’t completely believe it,’ he admitted.
‘And that’s why I’m going first!’
Beck took off his snowshoes and moved out onto the bridge on all fours, with the rope round his waist, while Tikaani paid it out through his fingers behind him. If Beck had been standing, then all his weight would have been concentrated on his feet. On all fours, his weight was distributed.
The first time he put his hand down on the bridge, there was a very slight pause and then something gave way beneath him and his hand moved another couple of centimetres. Beck froze, convinced the bridge was about to collapse. Then he realized it was just like when he walked on the snow. The topmost layer was frozen and it put up the tiniest resistance before his weight broke through to the softer snow beneath. He forced out a very brief laugh and kept crawling, trying not to think of all the thin air the other side of this very thin bridge . . .
It was over very quickly – he only had to crawl a few metres, after all. All that fuss for such a short distance seemed silly until you remembered the alternative – dying in a frozen mass of broken bones at the bottom of the crevasse. He stood up and dusted himself down, then turned back to Tikaani with a big smile on his face.
‘Your turn!’
Tikaani took off his snowshoes and dug up his rucksack on one side of the crevasse while Beck tied the rope around his own on the other and buried that. Tikaani tied his end of the rope around his waist, then dusted the snow off his pack, slipped his arms through the straps so that it was settled securely on his back, and crawled out over the bridge with much more confidence than Beck had done.
‘Whoa!’ Tikaani stopped almost at once, poised just past the edge of the crevasse. ‘I felt something go.’
‘Just keep going steadily,’ Beck called.
Tikaani looked up at him anxiously. ‘That’s just—’
Suddenly the bridge crumbled and Tikaani vanished from sight.