Mars pyramids

In Egypt in 1911, Marcus Scarmen in the ancient pyramid finds the door to the tomb with the image of the Eye of Horus. As soon as he is left alone, a green ray from the tomb hits him.

The TARDIS lands in Scarmen's family home, filled with Egyptian artifacts. In another part of the house, the strange Egyptian Ibrahim Namin argues with Dr. Warlock, a friend of the professor. Namin launches a mummy on Doctor, Sarah and Warlock, and all three soon meet Lawrence Scarmen, the brother of a professor, a scientist who, with the help of a Marconiscope, intercepted a signal from Mars. The doctor decrypts it as "Beware of Sutek" and explains that Sutek is from the powerful race of the Osurians. His brother Gore pursued him across the galaxy and defeated the Earth.

Namin tries to call Sutek through the portal-sarcophagus, but only calls his Servant, who burns the Egyptian, turns into Marcus Skarmen and proclaims death to all earthlings. Sutek orders him to cordon off the perimeter and build an Osirian rocket.

Meanwhile, the poacher Clements finds the mummy in his trap, and Marcus kills Warlock. The Doctor and Sarah are hiding in the TARDIS, and the Doctor shows her what will happen if Sutek wins, moving to 1980. After returning, the Doctor makes a silencer of Sutek's signal, but Lawrence, trying to save his brother, interferes with his activation. Mummy robots kill Clements and almost capture Lawrence's house, but with the help of Namin's ring, Sarah orders them to return to the estate.

The doctor decides to detonate the rocket with explosives from Clements' hut, but Sutek suppresses the explosion telepathically, and Marcus kills Lawrence. Then the Doctor through a spatial tunnel goes to Sutek and distracts him, allowing him to explode a rocket. He discovers the Doctor and decides to use his TARDIS so that Scarmen can turn off the Eye of Horus. With the control of his mind, he sends the robot and Sarah to the TARDIS to the pyramid of Mars.

Upon arrival, the robot strangles the Doctor, but the bypass respiratory system allows him to avoid death. He and Sarah set off through a series of riddled rooms to the central room, but unsuccessfully: Scarmen destroys the Eye of Horus and crumbles to dust. The doctor understands that Sutek will be released in two minutes and, together with Sarah, is hurrying back to the estate. Sutek moves from Egypt through a space-time tunnel, but the Doctor with the help of the TARDIS moves his end ten thousand years into the future, which means that Sutek will not be able to escape while traveling and will die of old age. The doctor and Sarah escape to the TARDIS, and the estate burns in flames.

• In this episode, Sarah wears a dress that the Doctor claims belonged to Victoria Waterfield.
• Sarah notes that the riddles are similar to those that were in the city on Exxilon (the series " Death to the Far Away "). One of these puzzles is a variation of the Problem of Knights and Liars .
• In this series, it is first mentioned that the lords of the time have a bypass respiratory system.