Anachrophobia

The Doctor, Fitz and Anji are forced to land in inhospitable terrain as something disables the Tardis. Reconnaissance proves it to be a planet in revolt, with colonists trying to break free from the harsh clutches of the Plutocratic Empire. The principal weapon in this war: time itself. Soldiers continually find themselves in Time Storms: without protective clothing, they are aged to death in seconds. The Tardis crew are picked up by empire personnel, and discover the empire's hope for victory: a primitive time-travel capsule. It is undergoing tests at the moment, but the men who return from these missions return horribly changed. They're picking up a terrible infection: anachrophobia; losing their time-orientation; travelling backwards and forwards within their own lifetimes; losing their minds. The Doctor is desperate to halt the spread of the disease, but his efforts are constantly frustrated. The plague reveals that there's a lot more about the motives of all involved than anybody had imagined...