It is August 1940 and Hornet Squadron regroup at a cliff-top air station on the South Coast of England. Morale has been low but fresh aircraft and pilots are arriving to prepare for the mighty attack that the Luftwaffe are suspected to be planning. The new boys are ribbed by the 'old hands' and, with the tension of constant readiness, simple pranks can easily get out of hand. But the glorious days of high summer mean that the enemy come over in endless waves, and Squadron Leader Barton has his hands full keeping the hard-pressed pilots at their sharpest.