Across history, the condition has been called "soldier's heart," "shell shock," or "combat fatigue". Today, Post-Traumatic Stress Disorder (PTSD) is increasingly common as service men and women return from Iraq, Afghanistan, and other combat zones. Veterans' centres in the U.S. have treated more than 1.6 million affected since 1990, including an estimated 100,000 from the 1991 Gulf War and an untallied total from Iraq and Afghanistan. That number also includes some 35,000 World War II veterans, because PTSD does not fade easily. Regardless of the months, years, and even decades that have passed, the traumatic events can flash back as seemingly real as they were when they occurred. The authors take us into the minds of PTSD-affected veterans, as they struggle against the traumatic events lingering in their minds, sometimes exploding into violent behaviour. They also take us across history and into current experiences and treatments for this haunting disorder. The authors explain how and why PTSD develops, and how we can help service members take the steps to heal.