The TARDIS arrives in the year 2540 on board an Earth spaceship, which then comes under attack. The crew perceive the Doctor, Jo and the attackers as Draconians, whose empire currently rivals Earth's for control of the galaxy. The Doctor and Jo, however, see that the attackers are really Ogrons.
The Ogrons stun everyone on board and steal the ship's cargo - including the TARDIS. Accused by the Earth authorities of spying for the Draconians, the Doctor is sent to a penal colony on the Moon while Jo is placed in the custody of a Commissioner from Sirius 4 - actually the Master.
Planet of the Daleks:
The TARDIS materialises in a hostile jungle on the planet Spiridon. Jo sets out alone to find help for the Doctor, who has fallen into a coma. She meets a party of Thals and is left in hiding aboard their crashed spaceship while they go to the Doctor's aid. The Time Lord, now recovered, learns of their mission to destroy a party of Daleks sent here to discover the native Spiridons' secret of invisibility