Whedon favorite Amy Acker has been cast as an important person from Agent Coulson’s pre-T.A.H.I.T.I. life.

Acker will appear as the mysterious cellist girlfriend mentioned in The Avengers movie and earlier this season in Marvel’s Agents of S.H.I.E.L.D., TVGuide.com reports. “Audrey” believes that Coulson is dead and doesn’t realize that he is protecting her from afar from someone from her past.

Acker will appear in the April 22 episode. The season finale will air on May 13. S.H.I.E.L.D. airs Tuesdays at 8/7c on ABC.