Water is patient... water just waits. Water always wins " November 21st 2059, and Bowie Base One - the first human colony on Mars - is destined for destruction in a nuclear explosion. This tragedy is a fixed point in history. The Laws of Time dictate that it cannot - must never - be changed. The Doctor arrives just as a viral life-form escapes from the Martian ice into the base's water supply. A single drop can transform a human into...