I’m 3,000 feet up above sea level, making my way down the highest peak in South Wales. Normally, this would be no drama, but it’s pitch black and I’m struggling against a 50 mph gale-force wind driving an icy rain straight back at me. I seem to be permanently blinded in one eye. I have lost all of my toenails and both feet are now a swollen and blistered mess. I’m running harder than Usain Bolt, but it’s like wading through treacle. All around me I can make out the orange emergency blankets of casualties who have given up and collapsed.

My only emotion when I see them is one of contempt. “Not good enough, mate.” Their failure spurs me on. I’m never giving up. Never mind the eye. I’ve got a spare one. My feet will heal up, and waiting for me at the bottom of the mountain will be a cup of tea and a cigarette. What more could a man ask for?

I’m over a week into the UK Special Forces selection course, but in reality, I’ve been preparing myself for years. At the back of my mind, ever since my first encounter with a couple of SAS instructors in the jungles of Kenya when I first joined up, I knew that this was where I would end up. During my time in the green (regular) army, I’ve put myself up for commando training with the Royal Marines and P Company (jump training with the paras).

I’d enjoyed my stint with the Marines—great bunch of lads—but there was never a chance I would transfer to a ‘rival’ service. I did fancy the parachute regiment, however. When I had completed the course, I had met the commanding officer who had congratulated us all for passing. Now, in the Campion world, even a fleeting introduction means a lifelong friendship, so I decided the best way to apply for a transfer from my existing outfit was to phone him up person-to-person.