"This mighty tome contains resources to empower you to run not just one but several campaigns weaving the Cthulhu Mythos into the horrors of the Second World War ... Overall, this is a mammoth globe-spanning adventure to keep you and your players happy and engrossed for quite some time." RPG Resources.org

This is the PDF version for download. 

Achtung! Cthulhu is a terrifying World War Two setting, fully compatible with the Call of Cthulhu, Sixth Edition and Savage Worlds roleplaying games.

Discover the mightiest terrors of the Mythos: the Great Old Ones, the Outer Gods, and their foul servitors and cultists; the spells and artefacts that can be brought to bear against them in mankind's struggle for survival; and the strange and unusual weapons that might just be the saviours of us all or prove to be our downfall.

Memories of a Past Better Left Forgotten…

"Discover the secret history of the earliest days of the war: a tale of murder, greed, and deceit, where forbidden knowledge is more highly prized than a man’s life (or his sanity); the quest for an ancient artefact of immense power; the race against the occult forces of the German High Command and even against time itself…”  

Shadows of Atlantis, the first major campaign for the Secret War includes: 

• A multi part adventure 328 page campaign that takes your investigators to the four corners of the earth and beyond.
• The forgotten story of one of the world’s most fascinating lost ancient civilizations: Atlantis.
• Four different teams of pregenerated characters, allowing you to experience the action from a different viewpoint in each theatre.
• New hideous creatures, terrifying threats, and unwholesome knowledge.
• Includes dual game stats for Call of Cthulhu and Savage Worlds.

Reviews

"What a campaign! When it comes to locations, plot globe-trotting, fighting Nazis, unspeakable horrors and what have you, Shadows Of Atlantis showcases in a brilliant way what A!C is about. You will definitely enjoy playing this, even though the Keepers might be swearing under their breath while preparing. Oh, well; no pain, no gain." RPG.net

RPG Resources Reviews Shadow of Atlantis

http://www.rpg-resource.org.uk/index.php?article=8120&visual=4

More about Achtung! Cthulhu

Discover the secret history of World War Two - stories of the amazing heroism which struggled to overthrow a nightmare alliance of science and the occult, of frightening inhuman conspiracies from the depths of time, and the unbelievable war machines which were the product of Nazi scientific genius - and how close we all came to a slithering end!

A massive gaming universe unfolds with the Achtung! Cthulhu guides, supplements, campaigns, miniatures and more.