Russell also includes further suggestions that the BBC books range and the Big Finish Productions audio range take place in parallel universes, and even has brief appearances from Peri, Evelyn Smythe, the Cyber-enhanced Evelyn from Real Time and Frobisher, as well as an alternate version of Mel who is a half-Silurian hybrid.
Russell suggests that the BBC books series and Big Finish Productions audio range are part of parallel universes, with appearances by characters like Peri, Evelyn Smythe, the Cyber-enhanced Evelyn from Real Time, Frobisher, and an alternate version of Mel who is a half-Silurian hybrid.