The town of Billaroo was devoid of a railway: or was it?

A group of bored schoolchildren stumble upon evidence of an ancient rail line passing through the town. They explore the countryside and find many more signs that some form of railway once existed. They consult the oldest residents of their town and are continuously told no such railway ever existed.

One of the girls, who is the daughter of the town's doctor, recalls that the well-known but constantly avoided local tramp, "Greasy Jack", is older than the other long-time residents. Reluctantly the group decided to visit the tramp in his filthy shack out behind the town cemetery. After winning his trust, the group are told of a sad, tragic tale which confirms their suspicions and also horrifies them.

Meanwhile, the trio of boys are engaged in an ongoing feud with some older boys. When two of them are bashed by the thugs, Greasy Jack intervenes, saving them from a more severe beating. The cowardly thugs swear retribution, and tragedy strikes. This triggers the decision by the group of teenagers to call a meeting of their parents and the police to tell all, not only about the mysterious railway but also the truth about Greasy Jack.