Set during World War One. After a catastrophic offensive, the surviving members of Y-Company find themselves lost in a gas cloud until they find a seemingly deserted German trench network.
They dig in but as tension mounts within the group and hope of rescue dims they realise that the place has a power of it’s own. Driven to the edge by the atmosphere of death and the phantoms they sense around them they turn on each other.
Only the youngest company member – Charlie Shakespeare (played by Jamie Bell) can see that they are being given choices which could lead to their survival or final demise.