,  Mark Ruffalo ,  Chris Hemsworth ,  Scarlett Johansson ,  Jeremy Renner ,  Tom Hiddleston , and  Samuel L. Jackson . In The Avengers ,  Nick Fury , director of the peacekeeping organization  S.H.I.E.L.D. , recruits  Iron Man , the  Hulk ,  Thor , and  Captain America  to save the world from