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. As a tropical cyclone churns across the Pacific, a cargo plane carrying nuclear weapons vanishes in the storm. Bicep and Invisible Six must recover the missiles before they fall into the wrong hands. Their mission takes them to a remote US military outpost in the Pacific. But the base soon comes under attack. Can Bicep and I-6 hold off an invasion long enough for backup to arrive? AGES: 10 to 11