S1, E1: Episode One tells the story of the founding of the SAS in the heat of the North African desert in 1941. David Archibald Stirling is an aristocratic dreamer who had once held lofty ambitions to be an artist or perhaps a famous mountaineer, but now, with the war in the desert reaching its most desperate stage, Stirling has a vision for a new kind of war: attacking the enemy where they least expect it - from behind their own lines.