Today I am travelling from the north-west of Scotland to the south-west of England in a day. The tiny, two-carriage train pulls out of Mallaig at 6.03am precisely. I have nearly six hours of rail travel to look forward to, all for the princely sum of £3.30.

I am armed with a packed brunch – which is finished before we reach Fort William, less than an hour down the line – and a fully-charged camera. This is my last chance for deer spotting – a fairly fruitless activity thus far. And there, just a few miles from the start, my patience is fully rewarded. By Fort William, the deer count has reached 17, and on Rannoch Moor I find myself recording a phrase dredged up from my microbiology days – too numerous to count.

I cannot get decent pictures, as they are all too far away or running from the train, and I finally give up and put the camera away after my very own Kit-Kat moment: four beautifully posed animals, close to the railway line, just as I am unwrapping a chocolate bar!

The rest of the journey is a patchwork of impressions, some captured as photos, some just memories: my Harry Potter moment on the Glenfinnan Viaduct; a great view of (most of) Ben Nevis; snow-capped mountains; and wide open spaces.

We started as 3, became 5, then (a different) 3 and finally then there was 1. Sitting in Glasgow airport writing this, the Highlands and Islands seem a whole world away!