James Rollins 
Jake Ransom and the Howling Sphinx [EPUB ebook] 

The second in the action-packed Jake Ransom series from blockbuster adult author James Rollins. High adventure at its best.An ancient and priceless ruby — the Eye of Ra — has been found beneath the Egyptian sands in the Valley of the Kings.Legend has it the jewel holds immense power, but it has fallen into the wrong hands — which means trouble for Jake and Kady Ransom, and an action-packed adventure as the pair are catapulted into an ancient land of shifting sands, dark magic and dangerous enemies . . . Can Jake and Kady survive and outwit the Skull King himself?