No adults, no permit, no river map. Just some "borrowed" gear from Discovery Unlimited, the outdoor education program Jessie and her new companions have just ditched. Jessie and the others are having the time of their lives floating beneath sheer red walls, exploring unknown caves and dangerous waterfalls, and plunging through the Grand Canyon's roaring rapids. No one, including Troy, who emerges as the group's magnetic and ultimately frightening leader, can forsee the challenges and conflicts. What will be the consequences of their reckless adventure?

Jessie, Troy, and the rest of the crew from Downriver have returned to the Grand Canyon for adventure down the Colorado River. In the year since they last were together, each has changed; each feels more mature. But how will they interact now that they are facing new challenges—challenges greater than anything they've had to deal with at home? For Troy, it is a chance to prove he can be a team player, someone worthy of friendship and love. For Jessie, the river is the ultimate test. Does she have what it takes to row down the mighty Colorado? The only way to find out is to get into the raft and set off to face the thundering rapids and the powerful emotions that the river unleashes.