Giancarlo Esposito, Jennifer Morrison

Mirror, mirror on the wall, guess who's returning to Once Upon a Time this fall.

Giancarlo Esposito is set to reprise his role as Sidney Glass, otherwise known as the Magic Mirror, in the Season 4 premiere, TVGuide.com has learned exclusively.

Details on the return of the intrepid Storybrooke reporter are being kept under wraps, though the last time viewers saw anything of Sidney Glass, it was on the nameplate of a locked door in the deep recesses of Storybrooke hospital.



Worst ways to go: The most outrageous TV deaths

The Season 4 premiere, fittingly titled "A Tale of Two Sisters," will also introduce Frozen characters Anna (Elizabeth Lail), Elsa (Georgina Haig) and Kristoff (Scott Michael Foster). Esposito's former Revolution co-star Elizabeth Mitchell was recently cast as a potential villain with ties to Anna and Elsa.

In addition to Revolution, Esposito is best known for his Emmy-nominated turn on Breaking Bad.

Once Upon a Time returns Sundays this fall on ABC. Are you excited for Esposito's return?

Watch This Tonight — See why Extant is our editors' pick: