 Kolchak looks into several instances of spontaneous combustion, where the victims were suddenly incinerated as they dozed. He finds that the apparition of a renowned orchestra conductor was spotted at the scenes of the crimes, but the catch is that the conductor isn t dead. With the help of a gypsy, Kolchak learns that a vengeful ghost known as a "doppelganger" is at work, impersonating the conductor in an attempt to take over his life. When Kolchak himself is marked for incineration, he must avoid falling asleep until he can stop the ghost once and for all.