Stream (The Hollows of Time)

Professor Stream was a time traveller who had a history with the Doctor.

Stream arrived on Earth at some point after the Second World War, opened a small electronics shop in Tottenham Court Road, London, and secured a contract with the Ministry of Defence. He eventually made his fortune in the 1970s through electronics and gathering a following through his written work.

Stream boasted power and capabilities "far greater than any Earth human", which included mind control. He also knew how to operate a TARDIS. (AUDIO: The Hollows of Time)

Behind the scenes
In the original script for The Hollows of Time, Stream was an alias of ("Stream" being an anagram of "Master"). However, at the time that Big Finish Productions adapted the story, their permissions from the BBC did not allow them to confirm that Stream was the Master. Instead, they hinted at the identification through the Doctor and Peri's memories being "edited" to give them partial amnesia. Since the 2019 redesign of the Big Finish website, The Hollows of Time has been included in their collection for releases featuring the Master and has been included in 2019 and 2021 sales of releases featuring the Master.