This is the story of Sancho, a young giant otter, and his journey to adulthood. Rescued by local fishermen as a baby, Sancho was raised by veterinarian and researcher Carolina Vargas. As Sancho grows, Carolina knows that she must one day break their extraordinary bond and release him back into the wild.

But can Sancho survive alone in the world's biggest wetland? To prepare him for life as a wild giant otter, Carolina teaches Sancho how to swim — or at least, not to be afraid of the water — and how to catch his own food. It takes Sancho time to master catching piranha on the fly, but Carolina knows that once he's able to feed himself it will be time to say goodbye.

Set in the idyllic and ever-changing Brazilian Pantanal, we follow Sancho's story as he learns to survive in a world fraught with danger. She had the heart to take Sancho in, but will Carolina have the courage to send him back into the wild?