Urban Explorer

A group of four young explorers travels to Berlin to probe the Fahrerbunker, drawn by legends of hidden Nazi murals and relics. They prepare for a dangerous underground journey.

They begin their subterranean journey through tunnels, sewers, and catacombs beneath the city, chasing whispers of forbidden art and relics. The group hopes to uncover fragments that rumor says could rewrite parts of history.

Two Nazi men with a stubborn bulldog confront them and harass the intruders, forcing the group to pause their advance. The encounter signals the danger lurking in the subterranean relics and marks a grim turn in their expedition.

During the commotion, Kris slips on a wooden bridge and fractures his leg, bringing the group to a painful halt. Marie accidentally photographs their local tour leader, triggering a cascading disaster as tensions rise underground.

Marie and Juna decide to fetch help and slowly begin making their way back toward the surface club. Lucia and Denis stay with Kris to tend to his injury as the environment grows colder and more claustrophobic.

A grizzled, German-speaking man named Armin appears, and Denis tries to communicate with him in broken German, sensing something terribly wrong. The eerie figure marks the entrance of a far darker chapter beneath Berlin.

Armin reveals a disturbing routine: Kris is injected and knocked unconscious, while Lucia is strapped to a chair as Armin's cruel games begin. The chamber, lined with remnants of past trophies, hints at a predatory mechanism controlling the underground.

Denis confronts Armin but is quickly overpowered and injected himself, joining the vulnerability of the group. Lucia fights in the chair as Armin asserts control over the entire chamber and his malevolent appetites become undeniable.

Denis frees Lucia but discovers a severed head in a refrigerator and a naked corpse in an upside-down display, evidence of the brutal fates that haunt the tunnels. Marie and Juna's fates are sealed as Armin exerts a grisly display to terrorize the survivors.

Kris awakens disoriented to the truth that the elder man who offered assistance has been killed by Armin. Armin drags Lucia from a subway car into a dark chamber, and Kris crawls toward the sewers, seeking an escape.

Lucia drags herself along rails and walls as the injection's effects blur her vision, while Kris continues to search for an exit. The pursuit intensifies as Armin circles the tunnels, matching the predator to his prey.

In the brutal denouement, Armin cleans up the bloody scene and leaves no trace of what happened. Kris finally crawls into the sewer waters and escapes into the open city, but the next day children discover what might be his body, while Armin remains at large in the depths.