Time travel is a naturally occurring phenomenon. Every four and five years, invisible, time travel doorways open and close. Any person or creature caught within the magnetic, gravitational pull awakens incoherently to a future world. Leigh, a psychology doctorate graduate, awaits the latest event. One traveler arrives: a 28-year-old runaway slave named Harriet, who flees before Leigh can make contact. With the aid of her brother, Stan, an FBI agent in D.C., Leigh begins a desperate search for the 19th century traveler. When John, a young, mysterious man arrives from rural Pennsylvania, Leigh and Stan work to uncover the truth of his story. All the while, Leigh knows she must find a way to convince Harriet to return to her past, or else history will be forever changed. Struggling to balance her duty to Harriet and the past with the actions of the peculiar gentleman, John, Leigh finds herself buried in a world of secrets that slowly unravel to the end.