Heather Longtreader visited the porch in the company of Emma, who introduced her to Maggie Weaver so that she could be taught about the purpose of Cloud Mountain to the Cause. Heather also witnessed painters at work, imagining scenes from the future Mended Wood.
After being apprenticed by Helmer, Picket Longtreader was ordered to report to the Mossy Porch every morning and afternoon to meet with Maggie. Heather, having heard troubling rumors about her family, fell asleep waiting to talk with Mrs. Weaver and then cried out in her bad dreams.
As Maggie attempted to offer Heather some comfort in her distress, Picket arrived for his second session with Mrs. Weaver. While Heather was outraged by the minor injuries Picket has sustained in his training, Maggie looked past them to see that Picket was enjoying the experience.
After speaking with Picket briefly, she sent him off to be looked over before counseling Heather to let her brother find his own path. Heather remained skeptical, particularly after learning that, during subsequent visits, Picket's exchanges with Mrs. Weaver consisted primarily of her listening to him talk.
Maggie's reputation spread beyond Cloud Mountain, at least as far as Halfwind Citadel, though those ignorant of her good character thought her crazy. Jo Shanks was among these for a time, bringing it up after Emma recommended that he visit Mrs. Weaver.
Heather and Emma later revisited the porch after Emma learned that she was the daughter of King Jupiter. Mrs. Weaver revealed that she was aware of the fact, having suggested sending Emma into hiding to her mother, Lady Glen. She also explained further details about the queen before Lord Rake arrived. It was then revealed that, in addition to connecting to Hallway Round, the Mossy Porch also housed a secret entrance into Cloud Mountain. Mrs. Weaver served as the guardian of this portal, with the means to destroy it with blastpowder to prevent its discovery.
Mossy Porch is a ledge atop Cloud Mountain that somewhat resembles a porch. It looks out in the direction of First Warren in the Great Wood, but the view is typically obscured by Cloud Mountain's namesake mists.