You will never read Denny Younger's name in any history book, will never know what he's done. But even if you did, you'd never believe it. The world as you know it wouldn't be the same without him. Denny was born into one of the lowest rungs of society, but his bleak fortunes abruptly change when the mysterious Upjohn Institute recruits him to be a Rewinder, a verifier of personal histories. The job at first sounds like it involves researching old books and records, but Denny soon learns it's far from it. A Rewinder's job is to observe history. In person. Embracing his new life with enthusiasm, Denny witnesses things he could never even imagine before. But as exciting a life as this is, there are dangers, too. For even the smallest error can have consequences. Life-altering consequences. Time, after all, is merely a reference point.