‘Your objective is this,’ Hector shouted above the wind as he marched along the line of recruits. ‘You are to imagine that there is a hidden weapons cache up in the mountains.’ He pointed to his right, at the slope that formed one steep side of the valley. It had looked unforgiving in the sleet. In the snow it looked impassable. ‘The cache’s position is indicated on a map, which I will give you. You will leave at two-minute intervals and try to locate it. Your objective is marked by a red flag. You will find a fingerprint sensor next to it. When you reach it, scan your fingerprint so we know you have arrived and how long it has taken you. If you do it in the allotted time, you will make it through to day three. If not, you won’t. A helicopter will arrive to bring you back down once everyone has checked in at the cache. In the meantime, you’ll have to find shelter. You’ll each have an emergency distress beacon. If you get lost, or you can’t take it any more, activate the beacon by pressing the button. It will send a GPS signal that will allow us to find you. But if you do that, you’re out. Any questions?’

Silence. Max glanced along the line of shivering recruits. Nobody looked like they were going to ask a question. He put his hand up. ‘How long do we have?’

Hector refused to catch his eye. ‘We don’t tell you. Do it as quickly as possible. You’ll either pass or fail. Any other questions?’

‘When’s lunch?’

Max looked to his right along the line and saw that it was Abby who’d asked the question. Hector simply scowled at her. He turned to Woody and Angel, who were standing opposite the recruits. Woody was carrying a pile of maps and compasses in clear protective pouches. Angel had the cigar-shaped distress beacons on lanyards. They walked to the left-hand end of the line and gave a map, compass and beacon to the boy standing there. Hector looked at his watch. ‘Go!’ he barked.

The first recruit looked bewildered. He looked round at the others, as though expecting some sort of help. But no help came. So he looked instead up at the mountainside that Hector had indicated. He consulted his map, looked up at the mountain for a second time, and then started to run through the snow. He became a grey ghost through the blizzard, then disappeared.

There was a murmur from the line of recruits. Hector was looking at his watch. When two minutes passed, he shouted, ‘Next!’ Woody and Angel handed out map, compass and beacon, and the second recruit, a girl, hurried off after the first.