I should have known the Harz would have the last laugh when I confidently told my partner I had packed "everything." Everything, it turned out, did not include my left walking boot, which I discovered sitting smugly by the front door approximately two hundred miles away. We were somewhere past Hanover when this dawned on me, and I spent the next hour practising my most charming grimace while my other half perfected the art of the meaningful silence.

We arrived at the Thale property in late October, when the Harz was properly getting into its autumn stride. The journey up from the south had been a masterclass in watching summer surrender. Green fields gradually gave up the fight, turning first hesitant yellow, then brazen orange, then that particular burnt umber that makes you want to buy a watercolour set you will never use. By the time we wound our way into Thale, the trees were having something of a final party before the serious business of winter set in.

The property sat at the edge of the village, and I will be honest: my first impression was dominated by the boot situation. I hobbled out of the car in a mismatched pair of trainers, immediately stepping into a leaf drift that came well over my ankle. It was cold, properly cold, that sort of damp German cold that gets into your bones and sets up camp. The kind of cold that makes you grateful for a solid heating system and slightly annoyed at your own footwear incompetence.

But then I looked up. The Brocken, that famously moody peak, was doing its autumn thing in the distance - half-hidden, half-revealed by clouds that seemed to be moving faster than they had any right to. The surrounding woods were at that precise moment of maximum colour, the sort of saturated display that makes you feel slightly fraudulent for just looking at it without some deeper artistic purpose.

The property itself was welcoming in that practical German way - no fuss, but everything where you need it. We dumped our bags and I immediately commandeered the better chair by the window, claiming it was for "observing the seasonal light" when really I just wanted to warm my feet and sulk about my boot. My partner, being the more practical half, went to investigate the local possibilities for replacement footwear.

Here is what I learned during that first afternoon alone with the autumn Harz: the season dictates everything. The daylight was already fading by four, a gentle reminder that we were on the wrong side of the equinox and there was no negotiating. The mist came down from the hills in a way that felt almost deliberate, turning familiar trees into silhouettes, then into suggestions, then into nothing much at all. I sat with a cup of tea that went cold too quickly and watched the world shrink to the size of the garden, then to the window, then to the reflection of my own foolish face.

When my partner returned victorious with a pair of hiking boots from a local shop that was having its end-of-season sale, I had reached that particular state of autumnal introspection where everything seems slightly poignant. The leaves falling, the light fading, the year winding down - it is all very symbolic if you have had enough tea and not enough proper footwear.

We walked a short trail that evening, just to test the new boots and justify our presence. The ground was properly soft from recent rain, and every step released that particular earthy smell that only comes in autumn. The last of the daylight caught the remaining leaves and made them glow, briefly, against the darkening pines. I found myself, despite the cold and the foolishness and the slight ache in my mismatched feet, grinning like an idiot.

That is the thing about arriving somewhere in the shoulder season. You do not get the easy pleasures of summer, the long evenings and the guaranteed weather. You get something more conditional, more demanding of your attention. The Harz in autumn does not perform for you; it simply carries on with its business of becoming winter, and you are lucky enough to witness it if you are prepared to put up with a bit of discomfort and the occasional footwear-related humiliation.

By the time we returned to the property, proper darkness had fallen and the temperature had dropped another few degrees. We lit the fire that had been laid ready, and I sat with my feet finally warm and properly shod, watching the flames and listening to the wind in the trees outside. Somewhere out there, the Brocken was disappearing into night cloud, and the leaves were continuing their slow descent, and the year was carrying on with its ancient business regardless of whether anyone was watching.

I thought about my abandoned boot at home, sitting uselessly by the door. It felt, in that autumnal mood, like a small lesson in impermanence. Or perhaps just a lesson in checking your packing list properly. Either way, the Harz had made its impression, and I had the right boots now, and the fire was warm, and tomorrow there would be more walking and more leaves and more of that particular cold, clear light that makes autumn in the mountains worth every minor disaster.

The mist was back by morning, and I did not mind one bit.