Hicks, Deron R. Lost art mystery.

"No matter how dangerous his adventures have been, Art has always been able to count on his best friend, Camille. Now that Camille is meeting her estranged father, Art wants to be there for her--which means going to London. But Camille's history professor father, renowned for expertise in British legend, is missing. When they visit his apartment, Art and Camille find a long-missing object that suggests the professor could be in trouble and solving a mystery related to London's history. Follow Art and Camille as they visit the Tower of London, National Portrait Gallery, and ride the "tube" in hopes of uncovering the truth before it's too late