The TARDIS materialises on Earth in the year 1911 inside an old priory owned by Egyptologist Marcus Scarman. Scarman has been possessed by Sutekh, last survivor of the god-like Osirans, who held prisoner inside a pyramid in Egypt by a signal trasnmitted from one on Mars. Sutekh desires his freedom and instructs Scarman to construct servicer robots - which look like Eygptian mummies - to build a missile with which to destroy the Martian pyramid UK)