Cyril and the team must survive a raging flooded forest and the agonizing sting of one of the jungle's most feared insects on their quest to sample a 200-pound pirarucu. Indigenous villagers help them track down the biggest fish so far but in order to sample the explosive animal, Cyril first has to battle it to shore without getting knocked out by its massive, bony head. To find the hulking piraiba, the crew must journey even deeper into the untamed jungle, where danger lurks around every corner with swarming black piranhas and roaring rapids that can sink their boat in a heart-beat.