Cyril and the team are asked to investigate the Giant Barracuda and African Cubera in Guinea Bissau. Their first task is to get a boat in the water, with the help of a village.
The trek to the Amazon is riddled with danger, not least of which comes from some of the fish species. Cyril hooks a Motoro Stingray and then must make every effort to keep clear of its highly venomous barbed tail.
Raging storms upriver have flooded the river banks and a ramshackle tugboat is called upon to move Cyril and his crew further up river into wild forest in search of a sizeable Muturo.
After a loss of a decent muturo, and endless problems with floating trash and water in the engine, Cyril finally lands a sizeable muturo and delivers the necessary samples to the researchers.