Private Detective Jerry Church (Patric Knowles) is asked to investigate the strange deaths of several recently acquitted men. The only clue is the mysterious calling card found on the body of each victim of a man known only as "Doctor Rx". Soon after taking the case, Church is on hand to see a man named Zarini acquitted, only to fall dead before he can leave the courtroom. To solve the series of murders, Church is kidnapped, his wife's life is threatened, and he is strapped to a table by Doctor Rx and prepped for an operation involving organ transplantation with a gorilla. Will Church survive this ordeal and unmask the killer? <br /><br />As far as the classic Universal horror (and horror is used very loosely here) films of the 30s and 40s go, The Strange Case of Doctor Rx is about as bad as you'll run across. I place it at the bottom of the heap with the unfortunate She-Wolf of London. I described The Strange Case of Doctor Rx to a friend as a Charlie Chan movie without any of the charm or interest of a Charlie Chan movie. Knowles' Church doesn't make for a very effective or interesting lead. He's just too bland. Lionel Atwill is billed second, but he has so little screen-time you'll forget he's even in the film. And when Atwill is on screen, he's reduced to playing the role of the most embarrassing red herring I've ever run across. Gwynne is okay as the love interest / wife, but she can't save the film on her on. The highlights of the cast are Shemp Howard and, especially, Mantan Moreland. They have a scene together involving shooting dice that's laugh-out-loud funny. Moreland, as usual, steals most every scene in which he appears. Other weaknesses: the films plotting is plodding, the direction is pedestrian, the mystery isn't very mysterious, and the horror is pretty much missing altogether. As most everyone who has written about The Strange Case of Doctor Rx has pointed out, the one scene of real horror feels like it was cut from another film. Other than Moreland, the one bright spot worth mentioning is the "look" of the film. Like most other Universal pictures from this period, the movie looks like a million bucks. Overall, a very disappointing affair that I'll be generous to and give it a 4/10.