When Bill takes the children on an expedition to the Middle East, they expect sand, sun, and stories. But when a disguised figure drops a note into Lucy-Ann's pocket warning them to turn back, the adventure begins. The river twists through canyons and ruins, its banks lined with signs of a forgotten people and dangers that lurx just out of sight. As Jack and Philip spot shadows in the rocks and Dinah uncovers a stone tablet with an unfamiliar script, the children realize this is no simple voyage. And when the river suddenly splits, taking their boat with it and they are separated in the wilderness, ane of them stumbles upon something no one was meant to find.