Frazer Hines
Hines' "Doctor Who" debut came in 1966, when he was cast to play the part of Jamie McCrimmon, the companion of the Second Doctor (played by Patrick Troughton). Originally intended as a one-off guest character, Jamie joined the regular cast and appeared in the series from 1966 to 1969. Hines reprised the role in a cameo in the 20th anniversary serial "The Five Doctors" (1983) and as a guest star in "The Two Doctors" (1985). Hines would appear in 117 episodes of "Doctor Who" in all—more than any other "companion" actor in the history of the series. The only actors appearing in more episodes are those who played the first four Doctors. Many of the episodes featuring Jamie no longer exist in the BBC's collection.
Stephen Wyatt
Wyatt's first work for television was "Claws", filmed by the BBC in 1987, starring Simon Jones and Brenda Blethyn. He was then commissioned by Andrew Cartmel to write two scripts for the science-fiction series "Doctor Who", which were called "Paradise Towers" and "The Greatest Show in the Galaxy", both starring Sylvester McCoy as the Seventh Doctor. His other television credits include scripts for "The House of Eliott" and "Casualty".