Whitney Cameron is in a quandary: he's attracted to his beautiful sister-in-law, Lynn, but also harbors serious suspicions about her. Her husband, Cameron's brother, died under mysterious circumstances, and now that the death of her stepchild, Polly, has been attributed to poisoning, he suspects that Lynn is after his late brother's estate, and killing everyone in her way.

Joseph Cotten
as Whitney 'Cam' Cameron

Jean Peters
as Lynn Cameron

Gary Merrill
as Fred Sargent

Catherine McLeod
as Maggie Sargent

Jack Kruschen
as Detective Lieutenant Harold Y. Cole

Barney Phillips
as Detective Captain Pringle

Freddy Ridgeway
as Doug Cameron

Harry Carter
as Wheeler (Uncredited)

James Gonzalez
as Joe Cunningham (Uncredited)

Ed Hinton
as Ed (Uncredited)