In December of 1943, a group of highly trained US and Canadian soldiers capture a crucial Nazi stronghold perched atop stunningly steep cliffs. The unit, with its vast range of capabilities and mission-specific exercises, became a model for the "Green Berets" and other special forces groups. David Saul knits together first-hand accounts and documents to show how these too-often forgotten heroes managed a string of incredible feats with strategic importance to WWII.