Since this was the 20th season, the people behind Doctor Who tried to reference past stories and characters as much as they could and initially conceived of this serial having a reunion meeting between the Doctor and one of the series’ original companions, namely Ian Chesterton. Scheduling conflicts kept that from happening, and other characters were considered before settling on the return of one of the few characters to run around with the Doctor for an extended period without actually being a companion, namely the Brigadier, who apparently retired from the military and became a math teacher for a prestigious British boarding school at some point.
That may seem a wee bit unlikely, but I’m not gonna question anything that brings the Brigadier back, even for a few episodes.
Our story begins when two boys swipe an old roadster that apparently belongs to the Brigadier and take it for a spin. The car, described as unique by the Brigadier and much faster than it looks, goes off the road, and one boy doesn’t wake up right away.
Wait, faster and unique? Was that Bessie with a paint job?
Anyway, one boy, named Turlough, is, we’re told, an orphan and a troublemaker. He may still be a troublemaker, but he’s hiding something: he’s also an alien. And his legal guardian says he can take Turlough back to his home planet if he eliminates a great evil on the guardian’s behalf. Turlough agrees, and then hits a transmat to a deep space craft with weird artwork in it.
Said craft almost hit the TARDIS, so the Doctor materilizes inside to look around. He finds the transmat, sees it came from Earth, and the rushes back to the TARDIS, barely noticing some strange kid already working on the console right away, and when the Doctor does notice, he isn’t even mad. Nah, he welcomes young Turlough inside. Nyssa thinks the kid seems nice. Tegan is wary of him.
So, the Doctor and Turlough return to the kid’s school so the Doctor can investigate the transmat device there, leaving the women in the TARDIS.
So, this all seems rather normal as described. I left a few details out.
First, Turlough’s sponsor is the Black Guardian, and he isn’t one of the good guys.
Second, the “great evil” Turlough has been asked to kill is the Doctor.
Third, if you thought the Black Guardian gave Turlough some kind of fancy weapon to strike the Doctor down with, you’re a bit mistaken. Turlough ends the episode by lifting up a large rock to smash on the Doctor’s head, AKA the Killer Croc method.
Though I am a bit mystified at the Brigadier. Turlough’s friend reports to the retired military man that Turlough and some mystery object just dematerialized, and the Brigadier says that’s impossible. Sure, he might just be keeping state secrets, but the Brigadier of all people knows just how possible that is. Then again, he looks weird without a mustache.