Piranhas, jaguars, and snakes...oh, no Marcus and Samantha Willoughby are prepared to face danger on their jungle trek. They expect trouble from creatures, but not from treasure hunters seeking to hold them for ransom. With the help of a friendly Indian, the brother and sister escape and take refuge in some ancient ruins. When the bad guys catch up, the twins face deadly peril again. They flee the lost city of Acara to take their chances on the run. Can they elude their pursuers long enough to return to their own time? Or will the jungle depths claim them forever?