Police constable Hamish Macbeth is baffled by two apparently unrelated mysteries: a huge quantity of table salt has been stolen from Rory Campbell's general store; and Geordie Robb, a local bully, is missing. Hamish outwits his superiors when he makes a connection between the two mysteries.

Major Maclean stages a robbery to make a false insurance claim. Before Hamish can settle things quietly, Inspector Bruce instigates a major surveillance operation.

On a mountain trek led by Colonel Don Maxwell, Hamish advises caution once the climbers have reached their goal, but Maxwell urges them on into a dangerous situation.

A hellfire sect leader sees the town as the new Gomorrah. Hamish's reputation is undermined and his tolerance stretched to the limit when he is denounced as the devil incarnate.

Whale-spotting trips and the disappearance of a local seafarer involve Hamish in a murky underwater investigation.

Village reporter Isobel stumbles on a story that could put her in the big league. She emerges with a fresh image and a hot new boyfriend, leaving Hamish squirming with jealousy.

Hamish turns a deaf ear to the local pirate radio station which is having a remarkable influence on the town. But when the radio authority sends a defector van to close down transmission, he is caught up in a conflict of loyalties.

Personal crisis takes Hamish to a remote island from which he intends never to return. But he is not alone. Meanwhile, his absence from Lochdubh is keenly felt when his over-zealous replacement makes himself a nuisance.