Margery Keeverton is looking after the estate of her uncle, Geoffrey Keeverton, who has just died. He had made a considerable amount of money from a fairground amusement arcade and has now left it all to her. While staying at her late uncle's house, she starts to receive nuisance phone calls which make it clear that she is being followed and which referred to an unpaid debt. Ken and Harry are asked to help. Because Harry rather fancies Margery, he is keen to help and even takes a week off work. Margery's solicitor, Peter Haymon, has very little confidence in Ken's abilities as an investigator. Harry takes Margery to the races but they happen to meet Haymon, spoiling Harry's plans for a romantic day out. A friend tells Harry that Haymon is ""one of the shiftiest lawyers in the Midlands"".

Ken and Harry keep watch on the house each night and their patience is eventually rewarded when they see a shady figure prowling round in the garden. They give chase but the man escapes, after giving Har