April 1914. Former US President Theodore Roosevelt and his son Kermit have embarked on a dangerous expedition down an uncharted river in the Brazilian Amazon. Threatened as they are by disease, drowning and starvation, an even greater peril awaits them when they are captured by a local Indian tribe, the mysterious Cinta Larga, and forced to hunt for a savage creature laying waste to the jungle's inhabitants. In their search for the elusive beast, they find unexpected allies in a young mother and her half-caste child. But with hopes, dreams and lives at stake, father and son must confront the...