Dr Thorpe believes that Glover needs a blood transfusion and Figgis is the same blood group but Glover, being a snob, is not happy to be the recipient, especially when he hears that Figgis has received a transfusion himself from a West Indian. In the event it turns out to be Figgis who needs the transfusion and Glover who is the donor, as a result of which Figgis begins to act in an unusually upper class manner.
Dr Thorpe becomes an unlikely sex object when nymphomaniac patient Fiona demands they run off together and has written a complaint letter to the hospital board, whose chairman is her father, unless he agrees to her demand. The patients adopt various disguises in order to try and retrieve the letter from Fiona's room but ultimately it is Glover, in his persona as a suave specialist, that causes Fiona to switch her affections and save Thorpe's job.
Having got a book on psychology from the library Figgis takes it upon himself to analyze his fellow patients, alleging that Glover has a persecution complex and Norman is sexually repressed. After a disastrous group therapy session and an unsuccessful attempt to cure Norman's fear of cats it is Figgis who ends up having to see a psychiatrist - though she is young and pretty.
Norman is to marry the dull and plain Deirdre, rather than Jenny, and is most reluctant. Glover decides to flatter Deirdre in order that she might blossom but rather overdoes it so that she transforms into a glamorous, confident woman with no need for Norman. Dr Thorpe brings his marriage guidance counsellor wife in to speak to Deirdre but, having heard her speak glowingly of her encounter with an older man, gets the wrong idea.
Glover is charmed by new admission Harry Bridgewater - until it transpires that he is a prisoner who has come in for an operation with a guard in attendance. Having tried to pass himself off as a hardened criminal Bridgewater has to admit he is but a getaway driver but asks the patients to cover for him whilst he escapes - for a night - to have sex with his wife. They agree and persuade Dr Thorpe to assist them but will the convict return next day?
Charlie, an elderly drunk, arrives at the hospital, claiming that he is looking for his son, from whom he has long been estranged. The assumption is that his son is Norman though it turns out to be Glover, who, after initial disgust, starts to warm to the old boy, especially when Charlie promises to lay off the booze. In fact he gets so emotional that Charlie has to resort to playing at being drunk just to get rid of him.
The patients are discharged on the same day - somewhat reluctantly given their lengths of stay - and decide to have a reunion the same evening in a restaurant. By chance Dr Thorpe is there with Hilary, who is emphatically not his wife, and when Thorpe goes to make a phone call, Glover, seeing her alone, moves in and succeeds in going home with her. Figgis cannot stop himself from presenting the doctor with his latest list of ailments, causing Thorpe to flee. However next morning he gets an unpleasant surprise - Figgis is back on the ward having fallen downstairs and ...