Hugh Walpole 
The Dark Forest 

Set in Galicia at the Polish Front during WW I, the protagonist is an Englishman working for the Red Cross on the side of the Russians (a physical disability has kept him out of the armed military). He is a keen observer of human nature, profoundly empathetic and analytical, and although he is nearly always just outside the scenes of actual battle, he is absorbed with the interplay and conflicts among his fellow medics as their personalities alter and evolve under the pressure and strain of war. Walpole’s own experience with the Red Cross in WW I provided him with the background and, perhaps, the substance of his complex of characters. The oppressive maze of the forest is a nod to the dark wood of Dante and an appropriate setting for the conflicted inner self. I found the book a gripping and evocative read.