Kay Egan (Tanya Roberts) goes undercover as a nurse at a sex clinic because she thinks that Dr. Scott Callister (John Henry Robertson) and his wife, Jessica (Delia Sheppard), are responsible for the suicide of her sister.  Working undercover leads to Jessica meeting private detective Barry Mitchum (Nick Cassavetes), whose partner Monica (Gail Harris) died under mysterious circumstances while she was working undercover at the clinic.  Is there anyone working at the clinic who isn’t undercover?

This is a Jim Wynorski film, which means the plot is mostly just an excuse for the female members of the cast to disrobe.  Like many of Jim Wynorski’s films, it’s trashy but entertaining.  It’s a sex clinic where therapy comes in the way of hallucinations, strobe lights, and choreographed stripping.  Kay falls in love with Barry but, when she realizes that Jessica is into her, she used that to her advantage and buys Barry some extra time for his investigation.  Jan-Michael Vincent plays Warren Robillard, a twitchy associate of the Callisters.  It’s a Wynorski film all the way.

Jim Wynorski later said that he had a difficult time working with Tanya Roberts, who brings little of her old Charlie’s Angel spice to her role.  But John Henry Robertson and Delia Sheppard are a blast as the evil sex clinic owners.  Adult film actress Gail Harris is so sexy and likable as Monica that it’s a shame that she’s only has a few minutes of screentime.

Sins of Desire is a perfect example of why you couldn’t have late night Cinemax without Jim Wynorski.