Learn about Agent Phil Coulson's S.H.I.E.L.D. team, direct from the man himself, in this special video created for Geek Week on YouTube. See Agent Coulson, played by Clark Gregg, along with the full "Marvel's Agents of S.H.I.E.L.D." cast Tuesdays at 8:00 p.m. ET beginning September 24 on ABC!