Mr Benn is an ordinary fellow, living an ordinary life in an ordinary suburban house, at Number 52, Festive Road. One day, Mr Benn receives an invitation to a fancy dress party, and so, donning his bowler hat, he sets off to find a costume to wear. Unable to find a suitable outfit in the usual shops, he turns down a small lane and finds a shop filled with strange and unusual costumes. Inside, Mr Benn asks the fez-wearing shopkeeper if he can try on a suit of red armour; he then enters the changing room, puts on the outfit, and walks through another door... and suddenly finds himself transported back to medieval times. It is the first of many amazing and extraordinary adventures for Mr Benn…