Shannon Phifer

In the final minutes of Valhalla Rising, Dirk Pitt discovered, to his shock, that he had two grown children he had never known, 23-year-old fraternal twins born to a woman he thought had died in an underwater earthquake. Both have inherited his love of the sea: the girl, Summer, is a marine biologist; the boy, himself named Dirk, is a marine engineer. And now they are about to help their father in the adventure of a lifetime.

As a member of the most powerful family history has ever known, 13-year-old Dan Cahill has been shot at, kidnapped, and even thrown into a pit with a deadly snake. He’s survived it all due to luck, smarts, and his older sister, Amy, who always sticks by his side. Now Dan and Amy are facing their greatest threat yet, an enemy who has found a way to use the source of the Cahill family power against them.