29 years after the events of Iron Sky, the former Nazi Moonbase has become the last refuge of mankind. Earth was devastated by a nuclear war, but buried deep under the wasteland lies a power that could save the last of humanity - or destroy it once and for all. An old enemy leads our heroes on an adventure into the Hollow Earth. To save humanity, they must battle the Vril, an ancient shapeshifting reptilian race, and their army of dinosaurs.

When Special Agent Watts and his Investigation Unit are called to the derelict Woodburrow Prison he thinks it's business as usual. But there's nothing usual about Woodburrow. A mysterious woman is found attempting to flee the scene and things begin to spiral out of control as an evil force picks the team off one by one. Soon Agent Watts is left alone to face what might be the world's most powerful evil... The Devil.