'True,' Lauren said, allowing herself a grin as she recalled the event that had brought her first attempt at basic training to an abrupt end. 'I suppose we'd better get cracking. You start translating the briefing. I'll go outside and bring in some snow to melt for drinking water.'

Lauren found a bucket and grabbed the torch out of her sled. She pushed the metal door of the container and squeezed herself and the bucket through a small gap, so as not to let out too much heat.

The sun was gone and only the tiny shaft of light from inside the container enabled Lauren to notice the giant white outline in the snow. Half convinced that she was overtired and imagining things, Lauren flicked on her torch.

What Lauren saw left her in no doubt. She screamed as she scrambled back inside the container and swiftly pulled up the metal door.

'What's the matter?' Bethany asked, turning sharply from her mission briefing.

'Polar bear!' Lauren gasped. 'Lying in the snow right outside the door. Luckily it seemed to be resting; another few steps and I would have trodden on it.'

'It can't be,' Bethany said.

Lauren waved the torch in her training partner's face. 'Here, take this. Stick your head out and look for yourself.'

It only took the briefest of glances to confirm it. The mat of white fur, with plumes of hot breath steaming out of its nostrils, lay less than five metres from the entrance to the container.

Once Lauren recovered from her near-death experience, the girls thought things through and decided that the situation wasn't too serious.

They could get all the drinking water they needed by leaning out of the metal doors and scooping up the snow around the entrance. Once they'd got enough snow, they decided to leave the giant bear in peace. It seemed unlikely the animal would leave itself exposed to the cold all night. Surely it would move away to find shelter before the sun came back up.

The inside of the container had now warmed up enough for the girls not to be able to see their breath curling in front of their faces. After their day in the cold, it seemed toasty. They stepped out of their boots and outer suits, hanging them on a line in the warm air above the gas heater, so that the moisture in them would evaporate overnight.

The metal floor of the container was cold to touch, so they put on trainers and laid out insulating foam mats retrieved from their sleds. They turned the heater up and lined icy tins of corned beef and fruit in front of it, as Bethany melted a saucepan of snow over a portable stove.

It took an hour to read the briefings for the final twenty-four hours of their course, under the flickering light of two gas lamps. The briefings only ran to five pages, but were written in languages with non-European alphabets that the girls had only started learning at the beginning of the course: Russian for Bethany and Greek for Lauren.

The gist of the briefings was simple. The girls had to unpack the snowmobile from its shipping crate and prepare it for first use: a task that involved s.c.r.e.w.i.n.g various bits together, lubricating the drive track and engine and filling the tank with petrol. From sun-up, they'd have two hours to make a thirty-five-kilometre journey by snowmobile to a checkpoint where they would liaise with the four other trainees for something the briefing ominously described as the 'Ultimate test of physical courage in an extreme weather environment'.

'Well,' Lauren said, as she dug her spoon into a can of corned beef that was warm and greasy on the outside but rock hard in the centre, 'at least the instructions for the snowmobile are in English.'

end.