No one knows the challenges of the battlefield better than the soldiers who face them every day. As part of a Navy SEAL team in Afghanistan, Brandon Tseng got to know all too well the gut-wrenching existential uncertainty involved in kicking down doors in a war zone: Would there be an IED on the other side? A suicide bomber? An enemy combatant with a gun or grenade? An ally who might look the same at first glance? Or just an innocent little girl, caught up in a conflict that to her means only terror, grief, and despair?