Riddle of the Sphinx

Can Malia and Jaden find the Sphinx before they exterminate humanity?
A mysterious entity known only as "The Sphinx" is planning to exterminate humanity. But who-and where are they? And how-and when will they carry out their plans? Can Malia and Jaden find them before it's too late?
If you like fast-paced sci-fi thrillers, you'll love fourth sequel to The Secret of Giza!