In this episode, Gaia goes white-water rafting down Costa Rica's most spectacular river to a remote ecolodge, to meet the people who fought to save the river from being dammed, and then visits the largest hydroelectric dam in Central America. She treks into the exclusion zone of an active volcano, and takes a dip in a hot spring, to understand how Costa Ricans have harnessed one of nature's most destructive forces. And on the stunning Pacific coast, she helps to build artificial reefs from unlikely recycling materials.