 Grimsdyke is sacked from his job as a medical officer at a men's prison, for his misbehaviour with the Governor's daughter, so he enrolls in a refresher course with his old medical tutor Sir Lancelot Spratt (James Robertson Justice), who is determined to make him a successful surgeon.Grimsdyke discovers that a plum senior medical post is shortly to become vacant, and starts scheming to be considered, instead of his cousin, who has already been unofficially offered the job.Spratt and the newly appointed hospital matron clash, leading Spratt to 'volunteer' Grimsdyke to romance her and 'soften her up'.