Discover for the first time the story of the Organisation Todt, a hidden and brutal organisation overseen by Hitler at the heart of the Nazi machine.

Adolf Hitler described the Organisation Todt as 'the greatest construction organisation of all time'. It was from this organisation, headed by Albert Speer, that Hitler enlisted the nation's leading engineers and architects to build his empire of dreams. In time, it became a key partner to the SS and the Wehrmacht and led to the deaths of millions.

Unknown Enemy reveals the full extent of the OT and its long arm across Europe and the Reich. In wartime, its operations relied mainly on Germany's slave labour system, the largest exploitation of foreign labour since the end of the Transatlantic Slave Trade. Charles Dick takes us inside the OT's vast building projects throughout German-occupied Europe, from the Arctic circle to the Balkans, to tell the story of how engineers and builders – so-called 'ordinary men' – perpetrated some of the gravest war crimes under its banner.

Despite its extensive network, the Organisation Todt largely managed to slip under the radar of war prosecutors after Germany's defeat. Drawing on extensive new research, first-person accounts and survivor testimony, Unknown Enemy finally unearths its dark story.