A lifelong worrier, Philpott always kept an eye out for danger, a habit that only intensified when she became a parent. But she looked on the bright side, too, believing that as long as she cared enough, she could keep her loved ones safe.

Then, in the dark of one quiet, pre-dawn morning, she woke abruptly to a terrible sound—and found her teenage son unconscious on the floor. In the aftermath of a crisis that darkened her signature sunny spirit, she wondered: If this happened, what else could happen? And how do any of us keep going when we can’t know for sure what’s coming next?