The take-charge kids from John Fardell's The 7 Professors of the Far North face a summer packed with danger, excitement and suspense&#8212;flying airplanes, scuba diving, cracking codes and even taking a spin in the world's first antigravity backpack as they plunge into this fast-paced, high- flying adventure. Ben, Zara, Sam and Marcia begin their summer vacation by helping Professor Ampersand build the Silver Turtle, a high-tech airplane. This is thrilling enough, but things take an even wilder turn when a strange woman steals the airplane with the kids inside. She's trying to evade members of Noctarma, an international criminal organization that thinks the airplane is carrying a secret antigravity device that could be the key to world domination. They've got the wrong Silver Turtle, but they've also captured Professor Ampersand&#8212;and the kids will have to pull out all the stops to find the real Silver Turtle device before Noctarma does.