As a previous reviewer noted it's pretty damn slow for a thriller/horror pic. This central flaw is exhibited most clearly in that long and drawn out dead body disposal scene where director Curtis Harrington and scenarist Gene Kearney are too talky when they should be laconic (and suspenseful). Ironically, when the screenplay should be explanatory, as in providing a credible motivation for why Katherine Ross should invite an obviously dodgy Simone Signoret to live with her and hubby James Caan, Kearney goes all reticent on us and thus sacrifices what little credibility the story has. The result is your average scary movie which is not all that scary. Or disturbing. Or even interestingly deranged. C plus.