Schafft has infiltrated an underground escape line and plans to use it to smuggle German agents into Britain. Flint gets captured by them but escapes and uses the uninformed Gestapo to wipe out the agents.; McCallan transfers from the army to the R.F.C. and winds up in 42 Squadron. They are gentleman flyers, McCallan is working class. On his first mission he engages the enemy, against orders, shooting down three but costing 42 sqd. the experienced Lt. Spicer. Back on the ground he has an argument with Tyrell, who brands him a loner.