The town of Longhead Bay is forced to confront an invasion of alien forehead creatures that descend en masse. At the same time, local scientist Dr. Sheila Bexter is conducting experiments based on her theory that human intelligence is stored in the forehead. To prove this, she creates "foreheadazine" and tests the serum on her unsuspecting colleague, Dr. Latham—but things spin out of control, and the town is faced with a cataclysm of epic proportions.