"When the shadowwalkers were victorious in their battle against the Ant Queen, they hoped their work to save Caldera was done. But the rainforest has begun to rumble. Rumi, a scholarly tree frog who can control the wind, must bring his band of animal friends to face the greatest danger they've yet encountered--the giant volcano beneath the jungle itself. While the volcano roars, rumors of a mysterious evil blanket Caldera--the Elemental of Darkness has emerged and is building a legion of followers. When the shadowwalkers are forced to divide and conquer, Rumi finds himself an unlikely leader and must grapple with his own secrets before he can unlock the full scope of his magical powers. Can Rumi rally the shadowwalkers to save their rainforest home?" -- Amazon.com