There is a hidden doorway between two worlds.Harper Biel has a problem. She's on a mission to find her mother. It's been eight years since Phoebe Biel disappeared. Harper's mother was a brilliant professor at Cornell University, and her field of study involved quantum entanglement. Harper was ten when her mother left New York to spend a few weeks in Scotland working for Equinox Technologies. It was the last time Harper saw her mother.For eight long years, Harper planned and conspired to find out what happened to her mother. Harper's father simply believed what the authorities had told him-Phoebe Biel used the sabbatical from the university to make a new start, to abandon her husband and daughter. Somehow, Harper's father believed the story, but for Harper, she knew the love of her mother was still as real as it was eight years ago.Now, graduated from high school, the last summer vacation before Harper attends college, she's making the trip to Scotland. It is actually the birthplace of her mother and her father and his new wife can't stop her now that she's eighteen. She believes her mother didn't abandon her. Harper knows whatever happened to her mother has to do with Equinox Technologies.When Harper learns the truth of Equinox Technologies and what they are hiding, she's well on her way to the secret that took her mother away. It just might be her undoing as well.