In 1999, on the eve of the millennium, Tressa Novak wanders the streets of Boston, trying to make sense of her shattered life. Her teenage son has vanished without a trace and her twenty years of marriage are all but over. Ducking into an internet-bookstore to get out of the rain, Tressa makes an incredible discovery: an old microfilm machine that doubles as a time portal. Tressa endeavors to answer the age-old question: if you could go back in time and fix one thing, what would it be?