Five go to smugglers top

Plot
Following a terrific Easter Gale, Kirrin Cottage requires a lot of repair and Julian, Dick, Anne and George have no choice but to spend the holidays elsewhere, and find themselves looking forward to a couple of weeks at Smuggler's Top, a mysterious and and forbidding building at the summit of Castaway Hill. It is the home of Julian and Dick's eccentric school-friend, Pierre Lenoir (nicknamed Sooty), and his family - and soon the children become aware of and intriguing collection of secret passages, and discover that Uncle Quentin has been kidnapped! Is all it is seems on the quiet Castaway Hill or have the legends of smugglers been revived?