Every story about time travel is really about loss.This one began with a hairpin.Not the polished plot device of a science fiction novel, but a real silver hairpin -- the kind that leaves dents in bathroom counters when tossed carelessly beside the sink. The kind that catches in the light when a woman twists her hair up after a shower. The kind that disappears one day without remark, only to surface years later in the pocket of a child who swears he's never seen it before.I should know. I was that child.