With her kid sister tossed into the maelstrom of time travel, the decision to go save her seems like a no-brainer, but for renegade time traveler Evy Rivera, no alteration thus far has been a simple one.Constantine, the Roman warrior sworn as protector and keeper of her heart, refuses to stand aside while Evy blunders into danger again. Evy agrees to teach him how to travel, but her sister's safety is foremost on her mind and she has little patience for mistakes, triggering familiar friction during their training.When the first trip to Constantine's future to save Tiana triggers a new alteration, he must grapple with unfamiliar technology while protecting Evy and her sister.Trapped in the alteration, Evy must balance the handicap of an unrestrained Roman warrior in the middle of the 1800s with the feisty temperament of mathematical genius, Ada Lovelace.Tiana struggles to come to grips with her talents, unaware of the evil watching her every move. Will she repeat Evy's mistakes of trusting the wrong liar or will Evy rescue her in time?