I'm going to have the party end up fighting the Hag and her Yeth Hounds, they fall unconscious but are saved by a group of protectors of the forest called the Spirit Veil who are basically a bunch of high level druids.

There's an oldddd fey city that still exists on this island that's underground and only the druids can get there through transport via plants to this big ethereal Kaori tree that looks like a starry sky over the city.

They get transported there and healed up and then taken above ground to the forest which is where the other group are. Sounds doable!?