In this murder mystery, Joseph Cotten is somewhat smitten with his beautiful widowed sister-in-law, sultry Peters, until he begins to suspect she may be responsible for the death of her stepdaughter. After an autopsy reveals strychnine poisoning and because an inheritance, as well as an
existing step-son, is involved, Cotten is sure his hunch is correct and follows Peters on an ocean voyage, planning to entrap her before she does away with his nephew. Careful police work is well documented in the script. The basic premise--that most poisoners get away with their crimes because
poison is hard to trace--makes this a provocative and compelling movie.