In 1967, in the Motaba Valley of Zaire, Africa, a sudden disease ravaged the American mercenary barracks, and the death toll continued to rise. After the military doctor took the infected blood sample and left, the entire military camp was destroyed by a bomb, and the white-faced monkeys in the nearby woods screamed... Until the 1990s, a young American captured a small white-faced monkey in Zaire, Africa, and brought it back to the country for sale. Because it did not meet the buyer's requirements, the young man released the monkey, and then a new disease spread in the town of Cedar Creek in San Francisco. Colonel Sam (Dustin Hoffman) of the American Institute of Infectious Diseases received the news and immediately started research and treatment with his wife (Rene Russo) and colleagues. Because the disease is highly contagious, the government urgently dispatched troops to block the town, and those who wanted to escape were killed without mercy. At this time, a batch of confidential infected serum was sent, but Sam and a group of people found that this batch of serum could cure the disease in 1967, but it had no effect on the mutated virus today. Soon, Sam's wife was infected and dying, and the government decided to drop a bomb to destroy the entire town to eliminate the virus. Time is running out, Sam found out the source of the virus, and he must find the original virus carrier before the bomb is dropped.