Jon's Goth sister Zoe had a friend named Athena DeVries (who most people at school thought was a witch). And that morning, Athena discovered a folded piece of yellow paper sitting on her dresser. She opened it and read it, surprised that the person who wrote it knew that she was a magic user. She had never heard of a place called Loda's Majorum of Mysteries, but she definitely intended to investigate. Who knew? The store might even have something worth buying.
She casually touched the pendant that hung from her neck, feeling relieved that she hadn't taken it off when she went to bed the previous night (sometimes she was so tired that she accidentally removed it). The pendant protected her from uses of magic.
What she didn't realize was that the shop wanted her pendant, just like it wanted Jon's stone. While the pendant wasn't as powerful as the stone, it was still a magic item that the shop did not yet possess. The shop may have come to this reality because of the wishing stone, but there was nothing wrong with grabbing up a few other magical items along the way.