During World War 2, Ireland remained neutral. It might have been very different if those opposed to the government, including the IRA, had succeeded with a plan for the Republic to support Adolf Hitler's invasion of Britain. In other words, there was a real possibility that Britain's hard pressed military forces would face engagements on two fronts. Several top Nazi leaders including Himmler had expressed a keen interest in what became known as 'Plan Kathleen.'
However, Winston Churchill was having none of this. Using his newly formated SOE (Secret Operations Executive), or referred to as 'The Ministry of Ungentlemanly Warfare', the PM endorsed secret and dangerous missions to uncover any intentions and eliminate if necessary, those responsible for implementing them.
The story revolves around Flight Liutenant Jonny Munro, an ace Spitfire pilot based at the RAF Tangmere in West Sussex. He is unexpectedly propelled into a support role for SOE after a Luftwafffe pilot is shot down and escapes in a stolen Hurricane. In the process; the German kills a popular ground crew engineer, incurring a great deal of anger in the RAF and in the War Office.
The Luftwaffe pilot was not in uniform at the time of his escape and so was not shielded from prosecution by the Geneva Convention. Churchill, initially enraged, saw this as n opportunity to bolster public morale when prospects of a Nazi invasion cast dark shadows across the land. He demanded the German be located, captured and brought back to London and face British justice for murder at the Old Bailey.