Mark is desperate to prevent Jeff and Sophie going on a work trip together.
When Harry Saxon becomes Prime Minister, a reign of terror begins. But his dark ambitions reach far beyond the stars, and an audacious plan spanning the whole of time and space begins to close around the Earth.
The Doctor meets Martha Jones, a medical student in London, under unusual circumstances when her entire hospital is transported to the Moon. Can she learn to trust this mysterious stranger to save them all?
The mighty warships of a new Time Lord Empire arise from the ashes of the Earth. With the Doctor being held prisoner by the Master, and the Universe on the brink of war, only Martha Jones can save the human race.