Will's first year at Bridgeworld was full of excitement, and his sophomore year promises to have even more. His school is taking part in the Terrestrial Studies Program at Atlantis--a place that Will didn't even know existed. But he's not the only one going there... A team of terrestrials sets off on an expedition that will take them to Atlantis's front door...unless somebody stops them. What will happen if Atlantis can't remain a secret? What is hidden in the depths of the legendary city? And what will happen if Will's two worlds suddenly collide?