January 1945, Lower Silesia. As the Red Army’s winter offensive tears through the Eastern Front, SS-Obergruppenführer Hans Kammler oversees a secret Ahnenerbe program buried inside Project Riese — the Giant — at the unfinished tunnel workings of Sóboń, bored into the Owl Mountains around a rift that should not exist. Vril, the occult energy leaking through it, promises to remake ordinary soldiers into something beyond human. It also, with terrible reliability, destroys them.
A four-person Allied team — an SOE demolitions officer, his wireless operator, a Polish AK guide fighting to reclaim her own family’s land, and a liaison desperate to learn his son’s fate — infiltrates the site on what they are actually facing. What they find could change the war, if it does not consume everyone who touches it first.
As the front collapses and Kammler’s own exposure to the vril — which has broken every other subject — has been quietly working on him too, both sides converge on the same reckoning: some doors, once opened, cannot be safely closed — only destroyed, at whatever cost that takes.