Antique Necklace & the Mirror Girl Who Asked for Meaning & Interpretation

"Last night, I had a dream about jewelry. In my dream, I walked into an old shop at the end of a narrow street. The sign said "Antique Jewelry." I had never seen this shop before. An old woman sat behind the counter. She had silver hair and small, sharp eyes. "Looking for something?" she asked. "I don't know," I said. That was true. She smiled and opened a small box. Inside lay a necklace. A silver chain with a blue stone. The stone was the color of deep water. "Try it," she said. I put it on. The stone felt cold on my skin. I looked in the mirror. For one second, my reflection was not me. The girl in the mirror had long black hair. She wore an old-fashioned dress. Her eyes were green. Mine are brown. I blinked. The mirror showed me again. Normal. Just me. "Did you see that?" I whispered. The old woman just smiled. "The stone shows you things." I wanted to take the necklace off. But my fingers would not move. The silver chain felt stuck to my neck. I looked in the mirror again. The other girl was back. She raised her hand. Slowly, she wrote on the glass with her finger. "HELP ME" I stumbled backward. The mirror cracked from corner to corner, like broken ice. "Who is she?" I shouted at the old woman. But the shop was empty. No old woman. No counter. Just dusty shelves and spider webs. The necklace got tighter around my neck. The blue stone burned my skin. I grabbed it with both hands and pulled. Finally, it broke. The stone fell to the floor and smashed into pieces. Blue smoke came out of the pieces. It formed a face for one second. The girl with green eyes. Then it was gone. Then I woke up. I touched my neck. No necklace. No mark. Nothing. But all day, I kept checking mirrors. Just in case."