Having used their magic tree house to travel to India, where they must get a gift to help free the dog Teddy from a spell, Jack and Annie have adventures involving a tiger and other endangered jungle animals.

"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...