There's a strange woman called The Chronometrist who will not leave her alone. Garbled warnings from bizarre creatures keep her up at night. And there's a time portal in the keg room of the bar where she works.

Soon, Hallie is tumbling through the turbulent past and future Paris, making friends, changing the world -- and falling in love.

But with every trip, Hallie loses a little of herself, and every infinitesimal change she makes ripples through time, until the future she's trying to save suddenly looks nothing like what she hoped for...