This is one of the proverbial "must reads," especially for those who have served in combat and their loved ones. I am a combat vet, and while I saw nothing near to what the soldiers in the trenches in WWI experienced, I did see how killing and having friends killed affected some people. I am thankful that medical science now recognizes PTSD and can treat those suffering from it.
This story follows two men into combat at Gallipoli and France. One is the (semi) impartial observer, the other an idealist, a brave officer who leads his men with skill and professionalism. As the war progresses, the idealist begins to question his abilities, all the time pushing himself harder to do his duty.
There is combat in the book, but this is not a shoot-em-up. There are no set battles with hand-to-hand combat. Rather, the violence tends to be from the sky, random shellings and bursts of fire while the soldiers hug the trenches or are out on working parties. One minute, a group of soldiers is digging a communications trench, the next, they are blown apart by a Turkish shell.
The raison d'etre of the book, however, is not the fighting itself, but the transformation of Harry Penrose, the idealist who only wants to be a success on the battlefield. It is emotionally gripping, like being on an out-of-control train hurtling to the washed-out bridge. You can see what is coming, you are struggling to avoid it, but there is nothing you can do about it.
Once again, I never experienced anything close to that the soldiers in WWI faced, but to me, this is one of the best books I have read that give a feeling for the emotions that exist in combat. I highly, highly recommend it.