The TARDIS lands on Space Station Loma 1 on the fringe of the Earth Empire in the year 2551. Stan and his companions quickly learn that the station has recently been attacked by a race of aliens known as Sarons, and that the Empire has placed a military presence on the station headed by Captain Sebastian E'kar. Posing as traders, Stan and Ernest are questioned by E'kar when they are found in a restricted area and thrown in the brig with another prisoner named Carabas. Carabas informs them that E'kar is planning a coup and it starts at this station. The mercenary also hints that perhaps there are no Sarons at all and that it is all a ruse to give control of the station over to E'kar. The station is attacked, and Stan, Ernest and Carabas are given a chance for their freedom if they help defend the station. They battle robot sentries that had infiltrated Loma 1, and then make their escape with a wounded Carabas. Stan takes Carabas into the TARDIS to give him medical aid. There they learn that the station is under attack by a superior Saron attack force. Sending false command signals to the Saron fighters, Stan is able to turn the tide of the battle. Stan learns that his coordinate control circuits are nearly completely usless and rigs one last breath out of them so he can bring his TARDIS to the Saron mothership and stop E'kar (who has turned out to be a Saron). The TARDIS stops in the Vortex, the rematerialization circuit burning out under the strain of Stan's makeshift coordinate control system. The only way to rematerialize is to forgo all safety systems and plug the defective circuit directly into the TARDIS power source. Stan reprograms the coordinates for Gallifrey knowing that if the TARDIS isn't destroyed in the process, he'll need replacement circuits. Stan throws the switch, and a blinding orange light sears the TARDIS apart...