"From the very very beginning, when everyone thought it was crazy, I was thinking of The Chronicles of Riddick as a trilogy," said Diesel. "That would start with the movie you saw, and Pitch Black would act as a prequel that introduced you to the character. So in simple terms, in Chronicles 2 we venture to the Underverse. We knew we could get away with a PG-13 on the first one, but once you go to the Underverse it's rated R, because it's a place where war is the norm and there is constant, constant battling. Then on Chronicles 3 we will see Riddick return to Furia, to deal with the homeland."