Board Thread:Spoilers!/@comment-27060727-20160225003107/@comment-6175354-20160225123742

Chameleon-Guy wrote: It could be anyone, but I'm also hoping for a Robin Hood story, and to see Marian in the UW... even though I thought we were gonna leave that place in 5x20. I'm confused. At this point Hades' centric is probably 5x16, which is still weird because the flashback happens in Oz, I wanted a backstory for the Underworld. Whoever (of Emma and Co.) is left in Underbrooke, will probably leave in 5.19.... it is the Emma-centric, after all. While 5.16 will probably, be a flashback within a flashback type of episode.

When Eddy and Adam spoke about a potential Robin Hood-centric, they implied that it would take place before he met Maid Marian. If this is the case, then there is no reason to show her. If anything 5.21 will act as a bridge, between all the S5 storylines and the season finale.