Camp Century: The Bucephalus Incident — Ken Smith

Three children. One prince. A mysterious treasure as ancient as the world, itself. Lauren, Ben, and Charlie lead normal lives until the day an ailing, old army captain knocks on their door. He has a secret that he refuses to take to the grave with him. It's a secret that has the potential to unlock the past and change the future; a treasure that must never fall into the wrong hands. The lives of Lauren, Ben, and Charlie are destined to never be the same, especially when they drop in for a visit with one history's most famous conquerors, Alexander the Great. A single, burning question remains: Will they make it back home before time runs out?