Oscar Blaketon gets into trouble when two young criminals steal his car and run away from an accident they have caused, because he will not account for his whereabouts at the time of the accident and did not report the car stolen. Meanwhile the two criminals, Joey Sharp and Frank Collins, supplies drugs to the schoolgirl Lizzie Tyler and her friend Babs. Greengrass overhears how PC Bradley talks to a friend about buying classic motorcycles and spots an opportunity to earn a quit or two. He even knows where hen can get his hands on some if he can get Bernie Scripps to assemble them.

Somebody tries to break in at Jean and Derek Lester's cottage. Derek does not want to report it, because nothing was taken, but his wife is sure she heard voices. Dr. Merrick discovers that her patient William Seaton is being blackmailed. He has paid 300£ and left the money in a telephone box in Malthouse Street. He is not the only victim of the blackmailer. So is Barry Jones, who runs a refuge next door to the telephone box, and Mrs. Ventress' goddaughter Susan. The only common denominator to all three of them is Derek Lester who becomes the prime suspect, but he is being blackmailed too. Vernon Scripps has an appointment with the famous publisher Howard Dufton. Dufton wants Scripps to sell advertising space for a new magazine, but the new magazine may never happen because Dufton is nearly bankrupt. Vernon Scripps has an idea that might save him.