PC Michael 'Rosie' Penrose is given a compassionate move back to his home town of Ravens Bay, to be near his 'invalid' mother, Millie. He now resides with his flighty mum at his Auntie Ida's house, where his Uncle Norman spends most of his time in the garden (whether he likes it or not).

At work, Rosie is paired with PC Wilmot, a more experienced but also more reckless bobby whom Rosie often has to bail out of trouble and protect from the clutches of WPC Whatmough. Cigar-puffing Chief Inspector Dunwoody is their no-nonsense boss and Merv their short-sighted, inept supergrass.

Rosie also has a girlfriend, the demanding, clinging Gillian, whose snooty, factory-owning dad has little time for her PC boyfriend.