Board Thread:General Discussion/@comment-27364001-20160228034454/@comment-6175354-20160228151801

@NickyHelp, can you please stop taking every spoiler at face value?

Eddy and Adam already confirmed, that Operation Firebird refers to saving Hook. They also said, that all the characters would see visions while in the Underworld. For all anyone knows, Mary Margaret escapes the Underworld with Ruby, in 5.18.