'I bet the Wreckers' secret way is used by someone who steals down to the cove and takes the smuggled goods!'

The Famous Five have planned a holiday filled with swimming and picnics on the Ornish coast.
Then one day, they hear of an old plot to wreck ships down on the rocks - and it seems to have started again! Can the Five discover who is flashing lights from the lower on stormy nights, and save the boats from being robbed?