Hiding in the undergrowth at dusk just before the school holidays begin, Joe and Alex were waiting expectantly for the badgers to emerge from their sett. Instead the two brothers see a sinister fisherman making his way stealthily up the cliff path towards the disused aerodrome. They decide to follow, and so begins an adventure that leads to the discovery of an old wartime diary and a clash with a desperate gang of modern-day smugglers. The diary was written at a time when the aerodrome was manned by young pilots risking their lives in the defence of their country. Now the aerodrome is in use again, and the boys are in danger.