Jake Ransom and the Skull King's Shadow
Jake Ransom and the Skull King's Shadow is a young adult novel by James Rollins, part of the Jake Ransom fantasy adventure series. Plot synopsis. When a mysterious envelope arrives for Jake Ransom, he and his older sister, Kady, are plunged into a gripping chain of events. An artifact found by their parents (on the expedition from which they never returned) leads Jake and Kady to a strange world inhabited by a peculiar mix of long-lost civilizations such as the Romans, Mayans, and the Dinosaurs, a world that may hold  the key to their parents disappearance. But even as they enter the gate to this extraordinary place, savage creatures soar across the sky, diving to attack. Jake's new friends, the Mayan girl Marika and the Roman Pindor, say the creatures were created by an evil alchemist - the Skull King, Kalverum Rex. as Jake struggles to find a way home, it becomes obvious that what the Skull King wants most is Jake and Kady - dead or alive. Will Jake stay and help his friends or will he turn his back on his new friends? Jake Ransom and the Skull King