The Memory of Trees

Arthur would rise again, when he was needed. How long? It didn't matter. Merlin waited. "So many were slaughtered waiting for Emrys. I know you know how that feels. Waiting. While people die. I curse you, Emrys, do you hear me? To an eternity of useless tormented waiting!" Then in one moment, she put forth the charm... Post-series canon, ref. Tennyson's "Merlin and Vivien."