When Marcus and his mother arrive at the Diamond Beach Caravan Park, it is one big disappointment. For a start, it's nothing like the Diamond Beach that Marcus's mother remembers from her childhood, and Marcus can think of a hundred better ways of spending his holiday than in their crusty old caravan.

But it doesn't take long for the caravan to reveal its secret. And as Marcus is swept into the craziest, scariest holiday ever, he will need to use every ounce of his ingenuity to escape Miss Molpe's trap before it's too late.