As they journey by rail from Edinburgh to London, four strangers pass the time by sharing tales of trains that have changed their lives. A keen-eyed Scotsman recounts how he turned a friendship with a coworker into a romance by spotting an anachronistic train in an eighteenth-century painting. An Australian woman shares how her parents fell in love and spent their life together running a railroad siding in the remote Outback. A middle-aged American patron of the arts sees two young men saying goodbye in a train station and recalls his own youthful crush on another man. And a young Englishman describes how exiting his train at the wrong station allowed him to meet an intriguing woman whom he impulsively invited to dinner-and into his life.  Here is Alexander McCall Smith at his most subtle and enchanting, exploring the nature of love—and trains—in this utterly captivating story.