The exciting Doctor Who episode Earthshock was first broadcast from 8 March to 16 March 1982.it marked the final regular appearance of Matthew Waterhouse as the Doctor’s companion Adric and wasthe first to feature the Cybermen since Revenge of the Cybermen, in 1975. It startsAs the TARDIS arrives on Earth in the future, with Adric deciding he wants to return to his home planet Terradon, As the group explores a series of caves, they are caught by Lieutenant Scott’s team who along with Professor Kyle’s team are surveying the caves for fossils. However professor Kyle has not been seen recently so The Doctor helps Scott find Kyle’s team and discover that they are all dead and Scott suspects the Doctor of killing Professor Kyle’s team. Then the other men in Scott’s force are killed by androids, undetectable by the humans’ equipment. The Doctor then finds a powerful bomb that could destroy the planet, so he and Adric try to deactivate it.
Back In the TARDIS the Doctor traces a signal sent to a freighter spaceship outside the Solar system and decides to investigate the ship. Once aboard he and Adric are captured by the freighter’s security forces led by Captain Briggs. Meanwhile Villainous Cybermen, are hiding in one of the freighter’s containers and decide that this is their opportunity to take control of the ship. though the freighter crew, along with Tegan, Kyle, Scott, and his men, fight valiantly. Sadly their defences are foiled by Ringway, Briggs’ security officer who has betrayed them and has been working as a double agent for the Cybermen. Kyle is killed in the conflict and Tegan is captured. The Cyber-Leader reveals a dastardly plan to wipe out much of the planet while several visiting dignitaries are present for an interstellar alliance conference, however, should that fail he also has a backup plan involving crashing the freighter into the Earth detonating the freighters anti-matter engines.
So The Cybermen set the freighter on a high-speed collision course with Earth locking the navigation controls, the Doctor is forced by the Cyber Leader to take them to the TARDIS and leave Adric, Briggs, and other crewmen behind. EventuallyThe other crewmen manage to escape, however Adric stays behind determined to beat the lock and regain control of the ship and prevent it from crashing into Earth before it’s too late. Meanwhile the Cyber-Leader attempts to kill the rest of the TARDIS crew before they can rescue Adric and this has tragic consequences.