Board Thread:General Discussion/@comment-24589671-20140707192733/@comment-4062048-20140710000529

Gusey1397 wrote: Ok, so this confirms that Anna, Elsa and Kristoff will appear in this episode but also Giancarlo Esposito. I'm kinda of hoping that it is Sidney that appears because he was last seen in the Asylum but if the Magic Mirror appears then it means that Regina will probabaly be in the flashback. I can't wait for this episode now.

http://www.tvguide.com/News/Once-Upon-Time-Giancarlo-Esposito-Season4-1084083.aspx

Also, filming has begun and they have a reindeer https://twitter.com/AdamHorowitzLA/status/486898642314227712

YAY! Sven :D