James Ondersley, a genial middle-aged batchelor and very successful business man, has a passion for candied peel which he nibbles incessantly. The sweatmeat is supplied to him by one firm, but he occasionally receives gifts of his favourite brand. One box has recently been found to be impregnated with a deadly poison. Sadly, his pet dog was a victim of the outrage. Ondersley arranges a weekend party, all the guests being potential donors of the poisoned candy. Suspicion rests on most of them and a detective arrives to probe the mystery. Almost immediately afterwards, Ondersley is found by the detective, dead in bed. The investigation is in progress when Ondersley calmly walks in, alive and in perfect health. He was not murdered and the 'detective' is a member of his staff unknown to the rest. By this time Ondersley has learned the truth, which he relates to a tense audience of very embarassed guests. The secret is well kept to the last, the author contriving a most effective surprise denouement.