Poirot and Miss Lemon travel to Surrey to visit Miss Amelia Barrowby but arrive to learn that she has died during the night. Poirot had an odd encounter with her the previous day at a flower show when she made the odd gesture of giving him an empty seed packet. Upon returning home, he finds that she has written him seeking his assistance. Poirot suspects foul play and the pathologist confirms that the woman was poisoned with strychnine. Initial suspects are Miss Barrowby's niece and her husband, but when the dead woman's Russian companion runs away, Inspector Japp thinks he has the culprit. Poirot thinks otherwise.