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.
as John
as Nick
as Mrs Saunders
as Mr Saunders
as Doctor
as Schoolteacher
as Supreme Beefeater
as Munro
as Schoolboy (uncredited)
