A stranger walks into the Aidensfield Arms and collapses. George Ward recognizes him as Dennis Parker, who left Aidensfield and his wife and daughter seven years earlier. Parker claims he has no recollection of what has happened since he went away. He only hopes to find his family. But that may not be as easy as he thinks, because Parker is wanted for embezzling his former employer of 800£ on the day he went missing. Inspired by Hitchcock's "Strangers on a Train" Harold Jackson approaches Greengrass and wants him to set fire to his work shop. In return the Jackson will set fire to Greengrass' barn and they both can claim the insurance money. Greengrass wants nothing to do with it, but a few nights later his barn is on fire.

Eva Parker wants her dearly departed husband to be buried in the family grave in Aidensfield. But her brother-in-law Eli Parker will not allow his late brother to be buried in the family grave because of an old dispute. Jethro Woods was believed to have caused the death of Charlie Walker following a robbery against Walker's factory, but his guilt was never proven. Now he turns up in Aidensfield to Oscar Blaketon's great dissatisfaction. Walker's son Harry is not too happy about it either, and when Woods is the victim of vandalism and later gets killed in a hit-and-run accident Harry Walker is the most likely suspect. But Woods also claimed that he was framed and that he knew who really robbed the Walker factory, and he may have been killed to ensure his silence.

Someone sets fire to Bill Galloway's barn and he suspects Barry Dyson as a revenge for being sacked. Dyson even has a previous conviction for arson. But Dyson has an alibi. Dyson also says that he was sacked because he is seeing Galloway's daughter Sylvia. Then there is a fire at Jim Hobson's farm only hours after Dyson had been refused a job there. And this time Dyson has no alibi. Aunt Peggy is visited by an old friend, Denzil Witty. He has a plan on how to put advertising posters up wherever you want without permission from the council. But not everybody is keen on his idea and they take matters in their own hands.