Dublin on a cold April night. Anna Neale arrives home late and discovers her husband, David, dead in his study, his face a rictus mask of agony. Anna gazes with disbelief at the telltale marks on his skin. It seems David died from anaphylactic shock induced by a bee sting. But it is not bee season, and he has known all his life that he is allergic to the bee's poison. Anna finds a peculiar package addressed to David and begins to suspect that he was murdered.