Jimmy, @The Roots, @Tom Cruise and The Mission: Impossible - The Final Reckoning cast perform an a cappella version of the @Mission Impossible theme! #FallonTonight #TonightShow #TomCruise #HayleyAtwell #PomKlementieff #SimonPegg #GregTarzanDavis #TheRoots #MissionImpossible #JimmyFallon