Thelma and Patsy find themselves in a spooky house inhabited by a nut who is a mechanical genius and has made a robot who does everything. The inventor manipulates the robot's control board from a hidden room. The girls are soon in a panic. Patsy gets into an argument with the robot and loses the match of wits. Blackie Burke, an escaped convict, is using the house as a hideout, and this adds to the problems the girls already have.
