Matt is an 18-year-old Army Private recovering from a traumatic brain injury in a Baghdad hospital. He joined the military partly to secure college funds for his younger sister, Lizzy. He acts as a grounded voice of reason among his squadmates and shows genuine concern for local Iraqi civilians. Currently, he struggles with memory loss regarding the rocket-propelled grenade attack that hospitalized him.

Justin is an 18-year-old soldier and Matt's squad partner on patrols. He possesses a hotheaded personality and often rushes into dangerous situations, contrasting heavily with Matt's rational demeanor. Raised by a decorated Vietnam veteran father who pressures him to earn medals, Justin uses an abrasive sense of humor to cope with the stress of deployment.

Ali, whose full name is Ayyad Mahmud Aladdin Kimadi, is a 10-year-old Iraqi orphan living in a drainage pipe with his sister. He plays soccer with the American soldiers and demonstrates a talent for drawing, often illustrating detailed pictures of rifles. Malnourished and frequently begging for food, he forms a connection with Matt before the alley incident.

Charlene is a civil affairs officer and the only female member of Matt's squad. She maintains a tough exterior, frequently reminding the male soldiers of her weightlifting capabilities to prove her worth. She expresses skepticism about befriending Iraqi civilians, preferring to keep a professional distance.

Wolf is a soldier in Matt's squad known for his practical jokes and the distinctive wolf decal on his helmet. He enjoys the adrenaline rush of combat but struggles with the moral contradictions of their presence in Iraq.

Sergeant McNally is the leader of Matt's squad. He acts as the primary disciplinarian but occasionally lets infractions slide. He prioritizes the welfare and safety of his troops over strict adherence to military regulations.

Meaghan is an Army officer tasked with evaluating Matt's cognitive function following his brain injury. She administers memory tests and helps him process the frustration of word retrieval issues. Her assessments determine whether recovering soldiers are fit to return to the field.

Father Brennan is an Army chaplain at the Baghdad hospital where Matt is recovering. Constantly wearing an Oakland Athletics baseball cap, he quotes baseball players to comfort injured soldiers. He provides spiritual support for Catholic soldiers seeking absolution away from home.

Francis is a patient in the Green Zone medical ward recovering alongside Matt. He displays a heavy reliance on pain medication and constantly requests pills from the nursing staff. He keeps a Miss Piggy doll on his bed as a reminder of his young daughter back home.

Caroline is Matt's high-school girlfriend back in the United States. She participates in cheerleading and writes letters to Matt about ordinary teenage concerns like biology quizzes. Her safe, civilian life contrasts sharply with Matt's experiences in a combat zone.

Itchy is a stray kitten adopted by Matt's squad during their first week in Baghdad. Completely unfazed by the sounds of gunfire and explosions, the kitten serves as a comforting mascot for the soldiers at their base.

Dr. Kwong is the physician treating Matt in the Green Zone hospital. He monitors Matt's traumatic brain injury and explains the physical symptoms Matt experiences, including issues with memory retention and emotional regulation.

Pete is a young hospital orderly who assists in the medical ward. He shares his iPod earbuds with Matt during wheelchair transports and occasionally smokes outside with the recovering patients, sharing stories about other injured soldiers.

Lizzy is Matt's younger sister, currently attending high school in the United States. Matt joined the military partly to secure funds for her future college tuition.

Matt's Mom is a single parent living in the United States. She worries constantly about her son's safety, prompting Matt to downplay his combat injuries during their phone calls to spare her anxiety.

Lieutenant Colonel Fuchs is a high-ranking officer working out of Saddam Hussein's former palace. He awards Matt his medal and oversees the preliminary questioning regarding the alleyway incident that caused Matt's injuries.

Lieutenant Brody is a first lieutenant who assists in investigating combat incidents. He approaches military casualties and local incidents with strict, procedural detachment, viewing civilian deaths in war zones as inevitable collateral damage.

Sergeant Benson was the previous leader of Matt's squad. He was killed by an improvised explosive device prior to the main events of the novel. His death deeply affected the remaining squad members, triggering erratic behavior from Justin in particular.

Figueroa is a member of Matt's squad who operates alongside Justin, Wolf, and Charlene during patrols. He prefers not to discuss the moral ambiguities or psychological stress of their deployment, choosing avoidance as his coping mechanism.