After losing his bid for the United States Presidency as a third party candidate, Theodore Roosevelt decided to take on the most dangerous adventure left on earth. He and his son, Kermit, accepted Candido Mariano da Silva Rondon's invitation to help him plot the course of the River of Doubt. The River of Doubt could just as easily have been named the River of Death. The river's rapids turned out to be much more ferocious than expected, cannibalistic natives dogged the group through most of the journey, and Murphy was their constant companion. The expedition lost men, supplies, and canoes. At...