It's an hour till sunrise. Starlight casts an ambient glow on distant snows that chill the wind. You can smell the heather and hear the crunch of dry quartz beneath your boots. You've planned the predictables, but the rest is chance. And chance is the point.
Up there, for sure, are things that will stop the clock. The fan of rays as dawn touches the ridgeline; the swallowing silence of the sheltered corrie, ice flutes like cut glass, an eagle perhaps, or a brocken spectre if the clouds move close. And then there's the stuff which happens in your head when the cogs and springs of consciousness are blasted clean by a summit wind.
But all that is to come, and just now, it's all about expectation. You know where you're going. You just need to find a way to the top of the mountain without falling off.
Nicholas Crane's Britannia: The Great Elizabethan Journey is released on DVD by Acorn Media, priced £16.99, tomorrow