> Similarly, there's a story where one of the trains gets off the tracks in order to smell flowers, or play, or something of that sort. The cure is to hide peop

> Similarly, there's a story where one of the trains gets off the tracks in order to smell flowers, or play, or something of that sort. The cure is to hide people in the field, who jump out and scare him back onto the track. There is, but it's nothing to do with The Railway Series (Thomas the Tank Engine doesn't appear in the first book) and is by a different author - you're thinking of Tootle.