Heartbeat (1992)

S13E21 Strangers on a Train

David narrowly avoids disaster when a man is ejected from a train, tumbling down the embankment right into his car's path. Merton looks into the incident and discovers a boy named Tommy running away from the scene, along with a crooked auctioneer who's planning to steal some precious antiques. In the meantime, Vernon has made the decision to establish a donkey sanctuary, while Ventress takes on a civilian administrative role at the police station.