At 90, the screeching, still lively Great Aunt Puddequet devises a novel means to determine which of her young nephews stands worthy of her inheritance: she will award her fortune to the relative who shows the greatest promise on her homemade Olympics field. Assisted--and occasionally bullied--by the trainer Kost, the five men of the family take up the sports of the discus throw, the long jump, and the shot put with competitive and varied results. Although no one is publicly pursuing the javelin toss, that sharp instrument nevertheless has a way of turning up on the field, the blade's tip stained with blood each time. Mrs. Puddequet watches her relations' training with great interest, though the old lady's constant companion--a nervous young woman once promised her share of the inheritance--and only grandson (now surrounded by rivals to the estate) survey the scene with considerably less amusement.
The tournament gets thrown off-track once the body of a tenant and Little Longer villager is found on the training grounds. Specifically, the luckless man is tied (with gymnasium rope) to a mermaid statue and submerged in the small mere. Inspector Bloxham tries to make sense of the tableau, and soon has a second death to investigate: Puddequet grandson Timon Anthony has been run through with a missing weapon that may closely resemble a javelin. Irritated at these mortal intrusions, Mrs. Puddequet tries to chase the police away from her Olympics, but finds a psychiatrist named Bradley (who has taken an interest in the Longer bodies) less easy to deter. While the inspector jumps from one suspect to another, Mrs. Bradley uses logic and psychology to identify the murderer from among the hopeful athletes and inheritors.