Ellie Sawyer has always felt more comfortable with books than people, which explains why she's a PhD history student neck deep in research and trying to complete her doctoral dissertation in time to graduate. But the final books she needs are half a world away in the tiny European kingdom of Lethersby, and the only time she can access the secretive Royal Castle Library is during the Christmas holiday.

Ellie is determined to get to the bottom of the mystery that has eluded Lethersby scholars for more than 100 hundred years by figuring out what happened to their long-lost queen, a young royal who disappeared shortly after the outbreak of the First World War. With the help of Mark, a handsome castle staff member who shares her love of history, she might be able to unravel the queen's story. But Mark is keeping his own secret from her, and what they discover together could change everything for Ellie-and the entire kingdom.