Anthony Dawson is having an an affair with his business partner's wife, Betty Gallen. So partner Basil Henson begins an affair with Dawson's wife, Zena Walker. When they meet, however, they are observed by Kenneth Cope and his girlfriend, who are wondering how they can make money off this. When Cope and Miss Walker murder their spouses in a way that convinces everyone it's a lover's suicide pact, they move in.
It's one of the Edgar Wallace mysteries produced in the 1960s. At slightly less than an hour in length, it's suitable as a second feature in a theater, or very slight trimming for packaging on television. None of the talent was famous, but they were very competent.
When Edgar Wallace wants to be nasty, he knows how to write the characters to do it. I enjoyed the hints of voyeurism, with Joe Trent and his girlfriend watching Zena Walker and Basil Henson; the calm way that Miss Walker goes about things so calmly, while Henson dithers. When the blackmailing begins, you begin to wonder what, if anything, we are supposed to believe about events not seen.
Usually I like to sympathize with someone in a movie, to invest myself in a good outcome; if it doesn't happen, it's a tragedy and if it does, it's all good. In a movie like this, however, where they're all thoroughly rotten, I find myself thinking that it would be for the best were they all wiped out.... and try to figure out how that's going to happen.