Riharri and her fey kin erected a magical grove in a forest near the outskirts of Northwatch. They built powerful wards around the grove and then brought the trees to life, ensuring that no one could enter without her permission.
The portal to the Arbor Isles is but a tiny pool of water within the grove that only spirits may travel through. Seeing as Riharri is immortal and can not be easily separated from her spirit, she has asked that the heroes of Northwatch venture into the realm to investigate on her behalf. To do so, they must be separated from their physical bodies, which she shrinks down to just a few inches tall, and places safely in a small magic sphere within the grove. (She finds it is much easier to hide and protect several small figures than full sized forms.) The heroes are tethered to their bodies with a magic thread that Riharri can pull to bring the ghostly heroes back to Cyrillia when her power is exhausted. And when they return, the heroes are reunited with their bodies, unharmed and fully healed.