The Mystery of the Vanished Prince, published 1951, is the ninth novel in the Five Find-Outers series written by Enid Blyton.
Fatty has returned to Peterswood village from a cruise holiday with Moroccan costumes for his friends Larry, Daisy, Pip and Bets. The four try on the exotic garb, at which point they receive an unannounced visit from Ern Goon, accompanied by his brothers, twins Sid and Perce. Fatty tricks Ern into believing the disguised children are actually relatives and friends of Prince Bongawah, a foreign royal who is purportedly at a summer camp alongside a caravan site where the three Goon brothers are camping.
Notably, Bets claims to be the prince’s sister, Princess Bongawee. The children take a walk, whereupon they encounter Ern’s uncle, the village policeman Mr Goon, who is also duped into believing the disguised children are foreigners.
