Amy Acker's hardly a stranger to the Whedonverse, so it's not particularly surprising that she would be appearing on ABC's Agents of S.H.I.E.L.D., however it is exciting to learn that she's playing a key role in Agent Coulson's story. We've heard him reference the cello player before. She's the woman in Coulson's past who believes he's dead. Acker will play her. Click To