Korean horror directed by Su-chang Kong. When a team of soldiers is sent on a rescue mission after an entire military barracks falls silent, what they find there is so horrific that they are ordered to burn the outpost - known as GP 506 - to the ground the following morning, destroying any evidence of the horrors that took place. The team find themselves with only eight night-time hours to explore the maze-like underground tunnels, find their target and uncover the awful truth.