Alfred Hitchcock himself praised this movie that was for him one of Barbara Stanwyck's most extraordinary parts.Besides,he did include Lucille Fletcher's short novel in his anthology "stories not for the nervous"(sic)
The story of this woman in her bed,who has heard on the phone someone is in danger,and who little by little discovers the horrible truth,is a first-class screen play which requires the viewer's attention,,or else he may lose the vital lead.The first people who enjoyed it had no pictures,since it was originally a radio broadcast,so they had to show a lot of imagination.The movie remains talky but the numerous flashbacks give it substance.The phone,is along with Stanwyck ,the star of Litvak's work;Burt Lancaster,a great actor though,only serves as a foil to both of them.50% of the dialogue consists of phone calls,that's what makes this thriller unique.
A strong connection with Hitchcock's work is the father's part(Ed Bigley).He is some equivalent of the Mother in many movies of his.The stuffed animals in his desirable mansion are a symbol of his daughter's lifelessness.(Coincidence?There will be such hunting trophies (and more) in his "psycho" twelve years later,and the topic is present in "the man who knew too much"(2nd version))
If you are fond of suspense,this is an unqualified must!