The mission was simple – bomb a Polish refinery making vital cold-weather fuel additives for the German army.

The target was easy – almost no anti-aircraft defences, as it was too far away for Allied bombers to get there and back.

This was launched one of the most daring adventures of the war – a game of bluff and double-bluff – as Major Barry Crofton and a small band of Free Polish troops tried to ensure that the bombers would fly home again once their job was done…