The Fourth Doctor masked his brilliant and inventive mind behind a facade of bohemian eccentricity. The longest lived incarnation of the Doctors so far, he was forced to change his body after losing a fight with his old enemy the Master and falling from a radio telescope to the ground beneath him...
Pyramids of Mars (1975)
The TARDIS is forced off course by a malevolent power and lands in the England of 1911. In a Victorian priory, the Fourth Doctor and Sarah Jane Smith discover murders are being committed by sinister cloth-wrapped mummies. Far away in a pyramid in Egypt, Sutekh - last of the Osirians - has been imprisoned for centuries by his brother Osiris. Sutekh takes over the mind and body of an archaeologist and plans to break free to destroy the past, present and future.