The fictional community of Gainesville, Missouri is in a tizzy. Mrs. Hoyle has been found dead in her bed on a pretty spring morning. It is immediately evident to the sheriff that she was poisoned, but was it by her own hand or that of her husband. He suspects the latter and so the sheriff has arrested Mr. Hoyle for murdering his wife. Dr. Merryman, the county coroner, and his part-time nurse, Miss Jaymes are tasked with examining the body and determining what type of poison was used to kill the woman. After a thorough examination, death by poison is confirmed, but not the type used, nor is there any conclusive evidence that Mr. Hoyle is responsible. Dr. Merryman and Miss Jaymes set out to find how who, if anyone, murdered the woman, or determine why Mrs. Hoyle would want to take her own life. What they learn along the way surprises everyone.