. "The Doctor and Romana learn the second segment of the Key to Time is on the planet Calufrax. Yet they arrive on a planet called Zanak, which has been hollowed out and fitted with hyperspace engines, allowing its insane, half-robot Captain to materialise it around smaller planets and plunder their resources."@en . . . . . "The Ribos Operation"@en . . . . . "The Doctor and Romana learn the second segment of the Key to Time is on the planet Calufrax. Yet they arrive on a planet called Zanak, which has been hollowed out and fitted with hyperspace engines, allowing its insane, half-robot Captain to materialise it around smaller planets and plunder their resources."@en . "99"^^ . . . . . "5.0"^^ . . . "--09-30"^^ . . "4"^^ . . . "4"^^ . . . . . . . . "The Pirate Planet"@en . . . "Fourth Doctor"@en . "The Pirate Planet (TV story)"@en . . . . . . . "16"^^ . "The Stones of Blood"@en . "Zanak and Calufrax, 1978"@en . .