In The Wasp's Nest, Hercule Poirot's come between a bitter triangle of lovers to prevent a sinister murder before it takes place. In Yellow Iris, a distressed phone call from a mystery woman brings Hercule Poirot to the hotel Jardin des Cygnes, where a man commemorates the four-year anniversary of his wife's sudden death - a death under very suspicious circumstances that Poirot himself witnessed. Gathered is everyone present on that fateful night and now Poirot must and a killer in the midst, before they strike again.