The Boy Who Turned Yellow
John and his class visit the Tower of London, where he loses his pet mouse. He falls asleep during a lesson on electricity, but with some help, he learns about it, invades the Tower, and saves his pet.
| Actor | Role |
|---|---|
| MMark DightamJohn | John |
 Robert EddisonNick | Nick |
| HHelen WeirMrs Saunders | Mrs Saunders |
 Brian WorthMr Saunders | Mr Saunders |
 Esmond KnightDoctor | Doctor |
| LLaurence CarterSchoolteacher | Schoolteacher |
| PPatrick McAlinneySupreme Beefeater | Supreme Beefeater |
 Lem DobbsMunro | Munro |
| NNigel RathboneSchoolboy (uncredited) | Schoolboy (uncredited) |