Suggestions of a Communist conspiracy cast suspicion on a murdered woman's Russian servant. Meanwhile, Poirot has a rose named after him, and a ceremony at the Chelsea Flower Show makes him the centre of attention. Hastings receives a packet of seeds and develops hay fever.

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 drawn into the underworld of London's Little Italy when Captain Hastings looks for a new car, but instead finds murder.

When Poirot investigates the mysterious death of a despised art dealer, he finds that he has more than enough suspects from whom to choose.

Lady Edgware has a dilemma in that her husband has consistently refused to give her a divorce. She asks Hercule Poirot to visit the man and see if there is any possibility of convincing him. When Lord Edgware is found dead, there is no great surprise, but there are a good number of suspects.

After collapsing with heart problems, Hercule Poirot visits a seaside health farm on Burgh Island. While there, the flirtatious heiress Arlena Stewart is found strangled on a secluded beach.