Six secret operatives are the military's top experts in covert ops and rescue missions. But this elite special force doesn't exist - at least not in the public eye. No one knows where they come from or to where they return. The group gathers for the most dangerous, most difficult, and most important missions and often operates in extreme conditions. They are known only by their code name: Invisible Six. Fighter pilots are performing routine landings on a US aircraft carrier when the impossible happens: the massive ship sinks in the South Pacific. Athena and Invisible Six are quickly deployed to the site to learn what happened and who is responsible. But the enemy is clever and soon makes I-6 look like the bad guy. Can Athena and I-6 unmask the enemy before another deadly attack occurs? AGES: 10 to 11