Synopses to Parts One through Six can be found at the top of Part Seven.
Part Seven: Cathy and her friends meet Joshua Wander, an interdimensional traveler who followed his mysteriously shrunken castle from Mâvarin to Shoppingtown. He claims to have no knowledge of the others' predicament, although a policeman who remembers being the Captain of Cathma's Palace Guard is dubious about this. Josh's castle has arrived looking a quarter its normal size, and his magical abilities are severely reduced. As the stranded magician looks through a spell book for answers, Fabian asks if he can look at the spell that brought Josh to Dewitt. Although the spell is written in an language that resists translation, Josh reluctantly hands over the book--and Fabian discovers that he can read it anyway.
Part Eight: Fabian announces that the spell is written in Lopartin, the ancient, magical language used on Mâton. The spell's footnotes mention the dangers of two much traffic between worlds, but offer no help for the current problem. Based on a vision, Fabian correctly identifies Josh Wander as a former student of nearly Syracuse University. Josh is astonished (and not especially pleased) to learn that he's "home." Fabian speculates about whether this fact contributed to the leakage between realities, and everyone wonders what to do next. Randy advises everyone to simply "wait."
Part Nine: Randy predicts that something is about to happen that determines what they will do next. He's right. The mall starts to bend and fold itself, and yet there's no apparent damage. Everyone starts running toward Joshua Wander's castle. Josh points out that, having been miniaturized, it's too small to hold much of anyone. Fabian dashes inside it anyway. He reappears in the doorway a moment later, looking a quarter his normal size. He urges everyone to run into the castle.
Part Ten: Fabian convinces everyone to go into the castle, because it's far safer than the mall at the moment. From the inside, sizes seem normal, but everything goes dark as the mall around the castle disappears. Beneath their feet, the castle starts to move.
Part Eleven: Cathy, Josh and friends chat as the castle makes its way between realities, making literary references and feeling more like themselves than they have all day. The castle lands safely. Fabian suggests that they all go see where they've ended up.
Part Twelve: When Cathy, Fabian and the rest emerge from Josh's castle, they become disoriented as the last of their memories of Dewitt fade, buried under their memories of Mâvarin. Before them is a portion of the mall, open to the sky and filled with dazed people. Josh points out that they are now speaking Mâvarinû, but Cathma does not remember speaking any other language, and doesn't quite remember Josh or the events of the day. She asks him to explain again who he is.
Part Thirteen: Portal
“All right: one more time,” the man said. “I’m called Joshua Wander, or Josh, or even JW. I’m originally from the same version of reality you folks are all from, even if you don’t remember it now for some reason.”
“But—“ Cathma began, but Josh raised his hand to stop her interruption.
“It’s true. Listen, I travel between worlds a lot, often involuntarily. Earlier today I followed my castle to Shoppingtown Mall in Dewitt, NY, where I met you and your friends. You were already half-remembering the lives of your counterparts in this world, but I don’t know the how or why of that. What I do know is that when the mall started to fold up around us, we fled into my castle, which brought us back here. There are a bunch of people still in my great hall, and under the circumstances I think that’s probably the best place for them right now.” He looked at Cathma with an expression halfway between interest and annoyance. “Does any of this sound familiar to you?”
Cathma nodded reluctantly. “It does—barely. So what you are saying is that I’m not really Cathma Selevar at all. I’m really….” She trailed off as she struggled to remember the other name.
“Cathy Salazar,” Fayubi said. “I remember now—as you say, barely. And I’m really Fabian Stockwell.”
“I don’t think so,” Rani said. “I think you’re mostly Fayubi the Seer, in the body of Fabian Stockwell.”
“So we’re who we think we are, but in the bodies of these otherworld people?” Carli asked. “Are you sure?”
Rani nodded. “That’s what the Infinite is showing me. I can sense a little bit of the Americans in each of us, but we’re mostly our Mâvarin selves.”
“Well, if I’m mostly Carli, does it really matter that this is Carl’s body?” Carli asked. “I mean, couldn’t we find the Americans and send them home in our bodies, with no harm done?”
“That would not be an acceptable outcome,” Shela said. “Technically you and Cathma no longer have the parental qualifications to rule Mâvarin.”
“And that’s nothing compared to Randy Foster’s problem,” Fayubi added.
Cathma deduced more than remembered who Randy Foster must be. “What problem is that?”
“Randy Foster is now a tengrem,” Rani said. “And I…I’m not. For the first time in over a year, I’m free of my curse.”
“Whereas Randy Foster now has his worst fears realized,” Fayubi said. “It hardly seems fair to leave him that way.”
Rani bristled. “Oh, but it’s fair to make me a tengrem again? What did I ever do as a human to deserve this?”
“It’s not what you did. It’s who you are,” Carli said. “What little I remember of Randy, he doesn’t deserve this any more than you do, and he wouldn’t know how to cope with it. You do.”
“Sheila Crouse also suffers through no fault of her own,” Shela said. “She now has my infirmity.”
“So what do we do?” Cathma said. “Somehow we’ve got to find our counterparts, and find a way to turn everyone back into themselves. And I don’t even know where we are right now.”
“Well, it’s a little hard to tell, with the mall here and everything,” Josh said, “but I think this is the same place Toujours Chez Moi was the first time I was in Mâvarin.”
“And where is that?” Jami asked.
“Just a few miles outside your city of Thâlemar, but away from the main roads.”
“That’s convenient,” Cathma said. “So we just need to get to the city. Most of our counterparts should be there, because that’s where we were before.”
“We don’t even need to do that,” Fayubi said. He was staring at nothing again.
“What do you see?” Cathma asked.
“They’re coming. All of them.”
“Here? How do they know to come here?” Wil asked.
“We’ll find out soon. Here they come,” Fayubi said. He pointed at a folding metal door in that closed off access to J.C. Penney in the truncated mall. As Cathma watched through the large storefront window, one of the dazed people got up from a plush chair inside the store, and slid the door upward. For a moment she could see the store beyond it, but then a blue haze covered the doorway for a moment. Through the haze came a line of people who had not been in the store at all. Cathma was struck by how odd it was, watching herself walk forward, Carli at her side. Next came Fayubi, and Jami, and Wil, all in their normal Mâvarin clothes. There was no sign of Rani. Last of all came Shela, supported by the one person Cathma had not expected to see, but should have.
“Li Ramet,” Rani said. “Of course. What have you done this time?”
Welcome to Mâvarin (info on the books and characters)