PC Michael Penrose,nicknamed to his embarrassment Rosie,returns to his native town,the resort of Ravensbay,when he learns that his exotic,pretentious mother Millie is dying. In fact it is a ruse to get him home where Millie and her sister Ida dominate Rosie and hen-pecked uncle Norman. Further woman pressure comes from girlfriend Gillian,anxious to get him to the altar. After a pointless visit from short-sighted informant Merv,Rosie goes to work and,along with slovenly colleague PC Wilmot,is called to a pub disturbance. Here they finally subdue an aggressive drunk ...
Rosie meets Chief Inspector Dunwoody who thinks he looks too young to be a policeman so he tries unsuccessfully to cultivate a sophisticated image by smoking a pipe. He also falls foul of Dunwoody by feeding two suspects he has been asked to mind. In the evening he and Gillian go out to an Italian restaurant with her parents,who dislike him. However he wins respect from an unlikely quarter when the two suspects also turn up.
Rosie's day does not begin well with Ida worrying about his safety and Millie about his appearance before Gillian waylays him on his way to work. He and Wilmot and called out to help patronizing DC Orr,who calls Rosie 'son' as they catch three youths who have burgled a games hut. Rosie is severely upset by Orr's attitude and he and Wilmot are much amused when Orr accidentally steals somebody's van to transport the criminals to the station.
Rosie and Wilmot do not take kindly to being called out on a Sunday to assist CID at the scene of a burglary. To add to Rosie's problems he is teamed with the formidable WPC Whatmough,who is nonetheless excellent at bringing to heel the spoilt son of a missing jeweller - who is not so much missing as sharing an intimate Sunday with his secretary behind his wife's back. Meanwhile Norman is forced to take Millie and Ida to church and Gillian argues with her father about her desire to marry Rosie - again.
After being called out to find a body on a beach and to try and talk a bugler out of the wardrobe where he is hiding Rosie returns home to find both his mother and his aunt trying to talk him out of his chosen career. Next day he goes on a date with Gillian,who also wants him to give up the force and join her father's firm. He refuses but finds himself softening in his attitude towards her.
Rosie and another young officer,P C Ellis,help an old lady who they believe has locked herself out of her vehicle but she is actually a car thief. After spending a depressing afternoon with lugubrious PC Dudley, Rosie and his family go to a cheese and wine party being organized by Gillian's mother Glenda to raise funds for the church roof. Gillian's father hopes to slip away on the pretext of buying more wine but is amorously pursued by Rosie's mother Millie.