Hand of Glory - Susan Boulton

In Passchendaele near the end of the Great War, Captain Giles Hardy is trapped on barbed wire, wounded in mind and body, convinced he should be dead. But Giles's true battle begins after he's rescued and sent home. In the small town of Stafford, he struggles with terrifying visions of the atrocities he's witnessed--and a recruit he served with.
The visions lead Giles to a man who exploits the grief of the bereaved with the help of a Hand of Glory, a mythical tool of thieves. A new friend, Agnes Reed, and the ghost of an old one, Corporal George Adams, aid Hardy in his investigation. Now he must catch the thief, destroy the hand, and lay to rest the men who will otherwise never leave the fields of Flanders.