Reluctantly cancelling his well-earned holiday, the physician cause in the TARDIS to trace and re-assemble the six segments of the Key to Time on which the stability of the complete Universe depends. Helped by the argumentative Romanadvoratrelundar and K9, he lands on the planet Ribos searching for the first segment and finds himself entangled in the machinations of two sinister strangers, Garron as well as the Graff Vynda Ka. Who are they? Is definitely Garron just a shady confidence-trickster dealing in interplanetary property? May be the Graff Vynda Ka only a power-crazed exile bent on revenge? Or are they both really agents from the Black Guardian, objective upon seizing the valuable Key in purchase to throw the Universe into eternal chaos? Risking his lifestyle inside the monster-infested catacombs of Ribos, the physician has to make use of all his wit and ingenuity to learn… John Leeson, who supplied the tone of voice of K9 in the initial 1978 Television serial, reads Ian Marter’s complete and unabridged novelisation, 1st published by Focus on Books in 1979.