Mack later goes on to become the director of S.H.I.E.L.D due to the ill health and subsequent death of Phil Coulson. In the final episode, "What We're Fighting For", Mack continues to lead S.H.I.E.L.D.
Due to Phil Coulson’s ill health and eventual death, Mack succeeded as S.H.I.E.L.D’s director. In the final episode titled "What We're Fighting For," Mack maintains leadership of S.H.I.E.L.D.