Late one night, Jim Qwilleran is disturbed by the shrill ringing of the telephone. His erstwhile landlady, Iris Cobb, now resident manager of the Goodwinter Farm Museum, is distraught. Knowing her frail state of health Qwill is concerned and becomes even more so when a piercing scream severs their connection.

Arriving at the museum he finds Iris slumped on the kitchen floor. But what at first looks like a natural demise from heart disease proves to be much more sinister. Once more the detective talents of Koko and Yum Yum, Qwill's sleuthing Siamese companions, are in demand in Pickax City.