Brannan Vines has never been to war. But she's got a warrior's skills: hyperawareness, hypervigilance, adrenaline-sharp quick-scanning for danger, for triggers. Super stimuli-sensitive. Skills on the battlefield, crazy-person behavior in a drug store, where she was recently standing behind a sweet old lady counting out change when she suddenly became so furious her ears literally started ringing. Being too cognizant of every sound—every coin dropping an echo—she explodes inwardly, fury flash-incinerating any normal tolerance for a fellow patron with a couple of dollars in quarters and dimes. Her nose starts running she's so pissed, and there she is standing in a CVS, snotty and deaf with rage, like some kind of maniac, because a tiny elderly woman needs an extra minute to pay for her dish soap or whatever.

Brannan Vines has never been to war, but her husband, Caleb, was sent to Iraq twice, where he served in the infantry as a designated marksman. He's one of 103,200, or 228,875, or 336,000 Americans who served in Iraq or Afghanistan and came back with PTSD, depending on whom you ask, and one of 115,000 to 456,000 with traumatic brain injury. It's hard to say, with the lack of definitive tests for the former, undertesting for the latter, underreporting, under or over-misdiagnosing of both. And as slippery as all that is, even less understood is the collateral damage, to families, to schools, to society—emotional and fiscal costs borne long after the war is over.