What if you were approaching the end of your thirties and all of the life milestones you took for granted in your youth suddenly seemed out of reach? On the eve of her thirty-ninth birthday, Maggie Piper doesn’t look, act, or feel much different than she did at twenty-nine, but with her fortieth birthday speeding toward her like a freight train, she wonders if she should. The fear of a slowing metabolism, wrinkling of her skin, and the ticking of her biological clock leaves Maggie torn between a desire to settle down like most of her similarly aged peers and concern that all is not perfect in her existing relationship. When a spontaneous request for a temporary “break” from her live-in boyfriend results in a “break-up,” Maggie finds herself single once again and only twelve months from the big 4.0. In the profound yet bumpy year that follows, Maggie will learn, sometimes painfully, that life doesn’t always happen on a schedule, there are no deadlines in love, and age really is just a number.