- Dawson Casting: Not a particularly bad case, but the actors cast as schoolboys look a little on the old side.
- First Appearance: Of Turlough.
- What Could Have Been: The Brigadier's role in the story was originally meant for Ian Chesterton, but William Russell was unavailable. Harry Sullivan was also considered, but Ian Marter was also unavailable.
- Write What You Know: Peter Grimwade based the public school setting on his own upbringing.
- You Look Familiar:
Trivia / Doctor Who S20 E3 "Mawdryn Undead"