Commando Comic #4429 'Boss Of The Sky' (2011)
 
Flight-Lieutenant Alvar Brenner was a real mystery to his fellow fighter pilots in the RAF squadron he flew with. He came from Balkovinia, a country very few of them had even heard of. And when he first went into action with them, he seemed to know every move the German pilots would make — as well as just how their aircraft would perform.
 
So they all began to wonder where he’d learned all this…and whether he might just be a Nazi spy planted in their squadron…