Mary Dixon's forthcoming wedding to Andy Crawford looks doomed when she starts receiving anonymous letters describing how he is having an affair with his ex-girlfriend Cora, who has recently returned to the Dock Green area.
A fresh spate of robberies in the Dock Green area bears all the hallmarks of having been perpetrated by a criminal known as The Captain. When he is then caught red-handed it seems that the police finally have their man. Or do they?
Kay Evans goes into The Station to report that her husband's suit and shoes have been stolen, but when Dixon explains that CID will investigate, she's reluctant, and tries to drop the complaint.