The series is based on the bestselling book by Richard Preston about the Ebola virus and its impact on humans. In 1989, the Ebola virus suddenly appeared in chimpanzees at a scientific laboratory in suburban Washington, with no known cure at the time. Working with a secret military SWAT team, a heroic U.S. Army veterinarian (Margulies) tries to stop the outbreak before it spreads to humans, but this puts her in mortal danger.