In April 1941, Major Hellemans returned to France and assisted by Captain Vandermies, smuggled the colour back to Britain.

Six months later, after fighting in the Battle of Britain, Jean Duclos, now a squadron leader, is persuaded by a fellow officer to return with him to retrieve the colours.

He contacts his former commanding officer, now living as a civilian in Ghent and secretly operating a resistance group feeding intelligence to the Allies.

Provided with a false identity and a cover story, Duclos returns to the farm, where his late colleague's wife and child still live.

Duclos must now travel through several hundred miles of dangerous and heavily guarded country to reach neutral Spain, from where he returns to England.