As a new threat emerges, tearing portals to other worlds and letting evil agents of unknown origin find their way to Earth, the team moves to shut down a new potential threat. But when the enemies blow up a museum to open another portal, what steps through is something they couldn't possibly imagine: It's Coulson. Except...it's not Coulson. Whoever this 'Sarge' is, he's definitely not Coulson. From 'Missing Pieces,' the Season 6 premiere of Marvel's Agents of S.H.I.E.L.D. Watch Marvel's Agents of S.H.I.E.L.D. full episodes online on ABC.com and in the ABC app.