(99/5B: The Pirate Planet)
Ice coated, uninhabited world which was captured by Zanak and reduced to a football-size husk. In reality, it was the second segment of the Key to Time. It was eventually recovered by the Fourth Doctor and Romana (5B).
- MACROMAT FIELD INTEGRATOR Component of Zanak's transmat engines. It burned out while Zanak and the TARDIS both tried to rematerialize on Calufrax at the same time. The Captain was ready to crush Earth to obtain the mineral PJX 18 (quartz) to replace it (5B).
- MADRONITE 1-5 One of the minerals extracted from Calufrax by Zanak. It was used by Mr. Fibuli to power the Psychic Interference Transmitter that the Captain used to stop the Mentiads (5B).
- VOOLIUM One of the minerals extracted from Calufrax by Zanak. It was used by Mr. Fibuli to power the Psychic Interference Transmitter used by the Captain to stop the Mentiads (5B).
- BALATON Pralix's grandfather. He was afraid of challenging the Captain of Zanak, and feared the Mentiads (5B).
- BRIDGE Citadel from which the Captain controlled the vast transmat engines which enabled Zanak to travel through space. It also housed Xanxia's time dams and the Captain's trophy room. It was blown up by the Fourth Doctor and the Mentiads (5B).
- CAPTAIN (OF ZANAK) Space raider and brilliant engineer who once commanded the ship Vantarialis. After he crashed on Zanak, he was rebuilt into a half-man, half-machine cyborg by Queen Xanxia, who secretly controlled his machine self. The Captain designed the huge transmat engines which turned Zanak into a pirate planet, stealing energy from the worlds it captured. The stolen energy was used to maintain Xanxia's time dams and was to eventually enable her to reincorporate herself. But the Captain secretly plotted to kill her, thanks to the energy gathered in his trophy room, which contained the shrunken remains of the worlds Zanak had plundered. The Captain ruled his crew by fear, with the help of his murderous pet, the Polyphase Avatron. With the Mentiads' help, the Fourth Doctor fought the Captain and prevented him from destroying Earth. The Captain was killed by Xanxia as he tried to kill her to avenge the death of his loyal first officer, Mr. Fibuli (5B).
- PRALIX Young man of Zanak, and Mula's brother. He became a Mentiad after absorbing the life force released by Calufrax. He led the Mentiads, and helped the Fourth Doctor and Romana defeat the Captain (5B).
- TIME DAMS Devices built by Queen Xanxia of Zanak to slow the flow of time to a virtual standstill for her dying body. They were secretly powered by the energy stolen from the worlds crushed by Zanak. However, the Fourth Doctor revealed that the time dams' energy needs grew in an exponential fashion, and sooner or later, there wouldn't be enough energy in the universe to prevent Xanxia's original body from dying. The time dams were eventually blown up by the Fourth Doctor and the Mentiads (5B).
- XANXIA (QUEEN) Evil, warlike Queen of Zanak who had nearly destroyed her planet in endless galactic wars, and was obsessed with eternal life. She rescued the Captain after he crashed on Zanak and rebuilt him into a cyborg, secretly controlling his machine half. She then made him build the huge transmat engines which turned Zanak into a pirate planet. She used the energy stolen from the worlds crushed by Zanak to power time dams to slow the flow of time to a virtual standstill for her dying body. She then used a cell projector to recreate a younger version of herself, whom she thought would one day become fully corporeal. She posed as the Captain's Nurse, while secretly ruling Zanak. But the Fourth Doctor exposed her secret and revealed that her plan was doomed to fail: Xanxia would always remain dependent on the life of her old body and, as the moment of her real death approached, the time dams would need ever greater amounts of energy to slow time even further. She killed the Captain as he tried to kill her to avenge Mr. Fibuli's death, but he had time to disconnect her cell projector. She died when the Fourth Doctor and the Mentiads blew up the Bridge and the time dams (5B).