After a tsunami washes over her Hawaiian island home, Darby Carter must pitch in to help get her grandfather's ranch back in order and make sure none of the horses drink contaminated water.

Darby's friend Cade has even bigger worries. His mother, Dee, hasn't been seen since the storm. With no other leads, Darby and Cade set out in search of Honi, Dee's beloved pony. But even if they can find Honi, will she be able to take them to Dee?