Hastings and Poirot are playing Monopoly when they are interrupted by Lord Pearson, the elegant Chairman of the London and Shanghai Bank. The banker asks them to investigate the disappearance of a Mr Ling - a highly-valued customer who before he went missing had arranged to sell Lord Pearson a map showing the location of a long-lost silver mine. Ling is found murdered, a young stockbroker is implicated, and Poirot has to untangle a complicated plot.

Matthew Davenheim, a rich banker, disappears on a walk from his country house to the village post office, and Inspector Japp of Scotland Yard is put onto the case. Poirot, who has developed an interest in conjuring tricks, bets Japp five pounds that he can solve the mystery without leaving his apartment.

Poirot visits a garden fete, where a wasps' nest adds to the tension. He meets the son of an old friend who has his girl-friend, a fashion model, with him, and Poirot soon suspects that they are both in danger. He has to solve a mystery which includes cyanide, failing brakes and mixed-up love lives. Meanwhile, Hastings has a new hobby which Poirot finds helpful in cracking the case.

Poirot is summoned to Marsdon by the owner of a country inn there to solve a murder. But the inn-keeper is a would-be thriller writer, and to Poirot's dismay the murder turns out to be fictional. Thankfully, though, there is soon a real (if seemingly supernatural) murder at the big house. Things get even more interesting when a young wife claims that a tree in her garden is haunted by a laughing ghost, and there are also signs of black magic from East Africa. Poirot lays a clever ambush to smoke out the killer,confident that he or she will turn out to be human.