Season Four of Once Upon a Time welcomes back Giancarlo Esposito as the Magic Mirror, aka Sidney Glass. He will appear in the first episode of season four, but there is no word yet on whether he will be back for more.
Meanwhile Elizabeth Mitchell has been cast in a mysterious role. Not much is known on what character she is playing, but she’ll be involved in the Frozen inspired story arc with connections to Anna and Elsa and is described as “possibly malevolent.”
Both Esposito and Mitchell recently starred in NBC’s Revolution.
via The Mary Sue