A series of mysterious deaths plague the life of conductor Ryder Bond. In each case, the victim is incinerated by supernaturally hot flames. As Kolchak investigates, he finds out that an arsonist, Frankie Markoff, was a fan of Bond's, and was killed in a penny arcade. His funeral procession crossed Bond's car, allowing the spirit to become a ""doppelganger"" and try to take over Bond's life. Each victim was burned to death when they fell asleep, and if Bond goes to sleep the doppelganger will take him over for good. Fighting sleep himself, Kolchak must exhume Markoff's body and reunite it with his restless spirit before he too bursts into flame.

In a oil company's laboratory, the air conditioning fails, and a primate creature attacks a scientist. The creature, and others like it, begin going on a rampage throughout Chicago. The oil company was experimenting with cell samples brought back from the Antarctic, which began growing when exposed to heat. Now these bizarre missing links are wrecking havoc. Despite the government cover-up, Kolchak investigates, and must track the creatures down to their lair beneath the old nuclear-research labs of the 50's.