Ep 20. The Planet of the Spiders, Episode 6
- June 8, 1974
The Doctor and Sarah Jane Smith, his companion, arrive on a strange planet overrun by giant spiders. The Doctor immediately realizes that the spiders are not indigenous to the planet and begins to investigate their origins. Meanwhile, the inhabitants of the planet, a Buddhist group, believe that the spiders are manifestations of their god and have been worshipped for centuries. The Doctor and Sarah must navigate through both the spider-infested planet and the beliefs of the locals to uncover the truth behind the spider invasion.
As they delve deeper into their investigation, the Doctor and Sarah discover that the spiders are being controlled by a powerful crystal that has been mined from the planet. This crystal is in the possession of a group of humans who have been using it to enhance their own psychic abilities. The Doctor realizes that this use of the crystal has attracted the attention of a malevolent alien race called the Eight Legs, who seek to use the crystal for their own purposes.
As the Doctor and Sarah race to stop the humans from using the crystal and prevent the Eight Legs from gaining control of it, they are aided by a young man named Mike Yates. Mike is a former member of the United Nations Intelligence Taskforce, the organization that the Doctor has worked with in the past. Mike left UNIT after being brainwashed by aliens, but he is able to overcome his conditioning and helps the Doctor and Sarah in their mission.
The final confrontation takes place in the Great One's lair, where the Doctor and Sarah must battle the Great One herself, a giant spider that is the leader of the Eight Legs. With the help of Mike, the Doctor is able to destroy the crystal and disable the spiders' control over the planet. The Great One is killed in the process, but not before revealing to the Doctor that there is another Time Lord present on the planet. The Doctor is left to ponder this revelation as he and Sarah prepare to leave the planet and return to their travels through time and space.