““There's a faulty signal on this line, about halfway through my journey. I assume it must be faulty, in any case, because it's almost always red; we stop there most days, sometimes just for a few seconds, sometimes for minutes on end. If I sit in carriage D, which I usually do, and the train stops at this signal, which it almost always does, I have a perfect view into my favourite trackside house: number fifteen. Number fifteen is much like the other houses along this stretch of track: a Victorian semi, two storeys high, overlooking a narrow, well-tended garden which runs around twenty feet down towards some fencing, beyond which lie a few metres of no man's land before you get to the railway track. I know this house by heart. I know every brick, I know the colour of the curtains in the upstairs bedroom (beige, with a dark-blue print), I know that the paint is peeling off the bathroom window frame and that there are four tiles missing from a section of the roof over on the right-hand side.””