The Master as "Professor Carl Thascalos" (or "Thascales"), with Ruth Ingram and Stuart Hyde. (TV: The Time Monster)

Professor Carl Thascalos, or Thascales, was an alias used by the Master (AUDIO: Mastermind) primarily to work at the Newton Institute on TOMTIT, experimenting and researching into interstitial time. Like other aliases, Thascalos was Greek for master, as pointed out by Jo Grant; (TV: The Time Monster)

Thascales was a visiting professor from Athens University who stepped in to take over after Professor Opfer's unfortunate and unexpected death. (PROSE: The Quantum Archangel)

Professor Thascales claimed to be a bookseller on Charing Cross Road in London, 1968, staging a mugging in the street to be saved by Jamie McCrimmon. As a thank you, he gave Jamie a copy of the Necronomicon to lure the Second Doctor to the Archons, Thascales having made a deal with them. (PROSE: The Nameless City)

Jeremy Winterdawn later accquired Carl Thascales's notes on interstitial time and began his own experiments, stating that Thascales had died after driving his car into a wall, his body burned beyond all recognition. (PROSE: Falls the Shadow)

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