Vislor Turlough was a new type of companion. Shifty, not very brave and quite happy to abandon his fellow travellers if he thought they were dead. Oh, and in the beginning, he was on a mission to kill the Doctor, too. All of those characteristics conspired to help make him interesting. Insipid was a term never applied to Turlough, played by Mark Strickson. Turlough left the TARDIS crew at the conclusion of Planet of Fire, his exile from his home planet of Trion lifted. His story continued in the Target paperback Turlough and the Earthlink Dilemma wherein Turlough builds a time machine and changes history. Few readers even got to the end of this book, though. It really was that bad. At 55, Strickson is still young enough to reprise his role, too. If the Doctor did meet Turlough again, it's far from clear how trustworthy or loyal the former companion would be. He's a very pragmatic character and if the Doctor brought danger to Trion, would Turlough help the Doctor? Such a setup could provide for some gripping television.