The summer of 2024, when Solar Cycle 25 reaches its zenith, finds Cy Riverton hiking to Dead Man's Drop Cliff to try to solve the toughest physics problem he has ever faced: How did Eddie Burrows disappear from there during 2024 Spring Break and end up in Pennsylvania in the year 1857? Marty Clark joins Cy. She hopes he will someday be more than just a friend. She plans to leave on a two-month history immersion tour and has no idea just how immersed in history she will shortly become. As a joke, Marty calls Cy's cell number while on the Cliff. From there she finds herself in 1748 western Pennsylvania, then 1758 Maryland where she befriends a Lenni Lenape woman, an English colonial woman, and Hunter, the dog. She tries to decide where she would be happier living if Cy cannot get her home right away, only to find herself being threatened by tribal warriors and British colonists alike. Cy communicates with Marty using text messages as they work to solve the physics involved with her travel back through time. Because law enforcement is already suspicious of him due to his involvement with Eddie, Cy decides to keep Marty's disappearance a secret. Their efforts become more urgent as FBI Special Agent Lee Hardin refuses to “cold case” Eddie's disappearance and pursues Cy relentlessly. Cy and Marty race against time and across eras in an effort to use the power of auroras to become reunited.
