Publisher's Synopsis
Philo Vance receives an anonymous letter warning of deadly danger to the wealthy Llewellyn family heir, Lynn. Eccentric widow Priscilla Llewellyn presides over a society family filled with greed, ego and unhappy marriage. Her secretary Doris becomes romatically involved with Vance, and the two are soon entangled in a mystery of murder and attempted murder involving poison and heavy water experiments.
