Lavender's class is on a field trip in the desert of Chiricahua National Monument, hiking down a ravine, when a flash flood strikes!

As the water hurtles down the ravine, everyone sprints for safety. Lavender runs in the opposite direction as the rest of her class and scrambles up a tree while the torrential river rages by.

When the waters finally recede, Lavender finds herself stranded in the brutal heat of the desert with only her ex-best friend Marisol, mean-girl Rachelle, and a boy named John. They are shaken, disoriented, and have just one pack of supplies and the most basic wilderness knowledge. Can they find their way back to safety? They will have to learn to work together in spite of their differences -- if they want to survive.