The title of Michael Pitre’s Fives and Twenty-Fives (Bloomsbury, $27) refers to the perimeters Marines try to maintain around possible roadside bombs to keep themselves safe from explosives. At the heart of Pitre’s novel is Lieutenant Donovan, commander of a platoon of combat engineers tasked with fixing potholes and defusing bombs on Iraqi roads. The story alternates between the lives of Marines in the years immediately following their discharge and that of their time in combat, during which a tragic event overshadowed their war experiences. It haunts them still. Like so many stories born of recent wars, this one is deeply affecting. Pitre himself was a combat engineer in Iraq and the vividness of his novel’s details testifies to the depth of their meaning for him. The strengths and vulnerabilities displayed by young men and women in impossible situations are heartbreaking and unmistakably real.