S03E14: A Clear and Present Danger

Three weeks after the destruction of both Primatech and Pinehearst, and the death of Arthur Petrelli, the now-villainous Nathan returns with a vengeance by persuading the U.S. President and the government to round up all people with abilities, leading to Claire, Ando, Hiro, Matt, Peter, as well as Tracy to become fugitives from the people who were their former allies.