Doctor Who
The Invisible Enemy (1) still
S15E0525 min· aired 10/1/1977

The Invisible Enemy (1)

TMDb6.7
Nexus es303327TMDb ep 167583TVDb ep 183299

Overview

Deep space, 5000AD. An Earth supply shuttle is infected by a strange sentient space-borne virus, which quickly spreads to the crew of the refuelling station on the moon Titan. Even worse, the Doctor himself falls victim. But why is Leela immune, and what is the virus's ultimate goal?