Private investigator Charlie Meiklejohn is called in by insurance companies to follow the trail of a suspected serial arsonist. The arsonist, Carson Danvers, has been on a fanatical crusade since the loss of his wife and son, burning down a series of old, shut-up wooden buildings in which random outbreaks of madness and murder have been occurring. Meiklejohn, with the help of his wife Constance, begins following the criminal trail, but finds himself teaming up with his quarry to face the source of these strange outbreaks: a malfunctioning alien space probe.