So at 22.20 tonight I saw the headlights of something sat with the engine in the southbound passing loop just up the track from my house in Kenilworth. It was waiting for a Voyager to pass it heading northbound, at which point it turned its engine on (which made a distinctive thukthukthukthukthuk noise) and it passed me. It was dark, so I only saw that it was a single loco or coach, coloured yellow, with lots of open panels down the sides enabling me to see people inside, and the glimpse I got of it doesn't match any of the trains pictured here. There were three headlights of equal brightness, one centred above the windscreen and two below. What was it, where was it going from and to, and what was its purpose?