I'm going to take you on the greatest adventure of your life. You probably'll never even thank me. Let's go.
Eccentric genius and misogynist Austin James explores the unknown from his private warehouse. His company, Serendip, runs just fine without him and Austin leaves the day-to-day business to a string of frustrated CEOs. What intrigues Austin are scientific mysteries: mysteries of the universe, mysteries of murder and mayhem. His newest secretary, Mickey Castle, is determined to get him involved with people and can usually prod him into investigating mysteries. From a man dying of exposure in his bedroom to a man strangled to death inside of a sealed nuclear reactor, from electrical aliens to a witch's curse, there's no mystery Austin won't investigate.
A teenage girl, Karen, flees to Austin's laboratory and asks for help. She claims that all of the adults in her neighborhood have been replaced by aliens. Austin and Mickey can't find anything wrong... and soon Karen is acting abnormally as well.