The Warm Hands of Ghosts

In a world torn apart by, war, a brother and sister fight to find each other. November 1917 : Canadian soldier Freddie Iven awakens after an explosion to find himself trapped under an overturned pillbox alongside an enemy soldier. A German. Against all odds, the two men dig their way out. But once in No Man's Land they realise there is nowhere they can go where they won't be shot as deserters or enemy combatants.
As the killing continues, they meet a man known as 'the fiddler' who seems to have the power to make the hellscape that surrounds them disappear.