Jonny Muir - Heights of Madness: In 92 days I walked and cycled 5,000 miles and climbed the highest peak of every county in the UK...What was i thinking

The world seemed about to end. Nature was wreaking her revenge. A shrieking storm laced with daggers of icy shrapnel. Ghastly drum beats of thunder as if mountains were cleaving and tumbling. Shadows were moving in, growing darker by the moment. A captive in a mist-obscured prison, my universe had shrunk to no more than five metres in any direction. The sky had succumbed. The valley had vanished. Life on Earth was no more. I was the only one left, a desperate stumbling soul.

An hour earlier, I had been sheltering in the sanctuary of the stone cairn on the 1,183-metre summit of remote Carn Eige, the highest point in the old Scottish county of Ross and Cromarty and the 12th tallest mountain in the UK. Now I was wandering aimlessly east across rock and ridge, willing the devilish furore to hoist me from this perilous perch and end the misery. I was lost, and with every step if such a thing were possible becoming ever more lost. The right way led to the west, first over Mam Sodhail, and then down a bealach which would return me to Glen Affric. If it still existed.

Instead, I was ghosting towards oblivion, time passing in a blur. It was five hours, maybe six, since I had left my bicycle on the midge-cursed shores of Loch Affric. They had been dreadful hours, the omens ill from the off. My last human contact had come with a thick-set Scot marshalling a quad bike along a path, which had been flooded by a swollen stream. I stood aside, watching the vehicle approach through the gloom and slanting rain. Hoisted on the rear of the quad bike was an adult stag, slain that day by a stalkers bullet, blood still dripping from its gaping mouth. Gazing into the beasts black eyes, I had shuddered as a wave of anxiety swept over me. It was little wonder nature sought revenge.

Quelling doubts and fears, up the mountain I had gone, in search of the pot of gold the summit. It didnt matter how, just get there. Sloshing through pools of green slime and brown sludge, fumbling across rolling scree and ankle-jarring rocks, staggering over grassy tussocks and wading through surging streams. Small steps, never pausing, eyes fixed on the ground. Heavy heart, heavy legs.

As I zigzagged up a thin track to the high ridge attaching Ciste Dhubh and Mam Sodhail, the wind lulled for a moment. During this peaceful calm the only sounds were the drip-drip-drip of raindrops on the hood of my waterproof and the distant pounding water of Allt Coire Leachavie. As I stepped on to the exposed ridge, the wind returned, a frantic, furious swirl, hurling icy pins that pricked exposed cheeks and forehead. From that moment till now, the storm had refused to leave. Relentless winds eddied, gyrated and twisted across Mam Sodhail and Carn Eige, at times forcing me to crawl on all fours, clinging to the mountains bare rock for dear life.

The concentration, the effort, the endurance: I felt I could bear it no longer. Before this interminable struggle, I had already tortured my hollow legs by pedalling 55 miles from Invergordon to Loch Affric. That was on top of the 4,200 miles I had cycled, from Cornwall to Shetland, and the 500 miles I had walked, all in the previous 90 days. The mountains, of course, had no sympathy. To them I was nothing but a 25-year-old scrap of skin and bone daring to breach their defences, millions of years old.

I was so tired, so very tired. Hands and feet were chilled until there was no feeling. My head was light and as thoughts relaxed, my stride became careless and clumsy. The roar of the wind bothered me less. I was calm. I plodded on. My legs were good at that. Just keep going, up or down, round and round, on a hill, on the flat, it didnt matter. Just keep going. But I was lost and losing it, and mountain madness was slowly gripping me. I was howling like a dog, swearing at the sky, jabbering nonsense. Repeating the words of the National Anthem in my head, over and over again, faster and faster, unable to stop, I knew I was in trouble. I had to get off this mountain.