Free The Phantom Limb by William Sleator, Ann Monticone

then by her elation. The image faded, and he was looking into the mirror box again. The phantom limb had returned and was trying to tell him something. It held up three fingers, as it had done before, and shook them at Isaac.
    â€œThree?” Isaac said out loud.
    The phantom limb shook in disagreement. It held up three fingers again.
    Isaac tried again. “Third?” It made him think of the games of charades his parents had sometimes played at their dinner parties. From upstairs, he had listened to them guessing and laughing. This, however, was deadly serious.
    â€œThree’s company?” Isaac suggested.
    The limb shook itself in exasperation.
    What on earth was the limb trying to say? Everything the phantom limb had shown him so far was important, so this must be important too. He would have to figure out its meaning in relation to the littlegirl—whoever she was—and her amputation of her doll’s arm.
    He quickly pulled his hands out of the mirror box. The phantom limb folded its fingers down over its palm in a sorrowful gesture, and left. Isaac put the box in the closet right away.
    He went downstairs to do something about dinner. Grandpa was not asleep on the couch, as Isaac had expected. Instead, he was looking at a copy of
Scientific American
. Isaac told Grandpa what the phantom limb had done, how it was trying to tell him something. He also told him about the “mirror dream” he had just had.
    â€œBut it’s not ‘three,’ ‘third,’ or ‘three’s company,’” he said.
    â€œHmm …” Grandpa squeezed his eyes shut for a moment, thinking hard. “Well, it could be ‘triptych.’ Or ‘troika.’ Maybe even ‘triad,’” he suggested.
    â€œWhat’s a triad, exactly?” Isaac asked.
    â€œI … I seem to remember it might mean two different things,” Grandpa said. “I think it could be a musical term for a particular three-note chord.”
    â€œWell, Joey Haynes
did
play the piano,” Isaac said. “But how could that connect with the little girlmutilating her doll? What’s the other meaning of triad?”
    â€œAny group of three, like three closely related people.”
    â€œI wonder if that’s what the phantom limb meant. But
which
three people? It still doesn’t make a lot of sense.”
    Grandpa shook his head and sighed. “I can’t stop thinking about that little girl and her doll. Whoever that girl is, she’s sick—and dangerous. We’ve got to get your mother home. Fast.”
    Isaac knew that. But he still didn’t know how he was going to zap Dr. Ciano with the spiral aftereffect. When—and how? He had to catch her off guard, so she’d injure herself and have to be away from work for a while. But everybody at the hospital was so vigilant. The whole idea seemed impossible.
    And he wondered: Who was the woman who had “accidentally” come into Vera’s room? Why had she smiled at him so strangely when she saw him right after the endoscopy? It was almost as if she knew what had happened to him.
    After dinner was over and he was back in his room, he puzzled over the whole situation as he sat at his desk, trying to concentrate on his homework. Hewas falling way behind in his schoolwork and would probably fail his upcoming tests. But he couldn’t concentrate on any of it. All he could think about was how he could use the spiral aftereffect and get Vera out of the hospital before anything really terrible happened to her.
    He remembered the sensation of his own room closing in on him. It had been very scary. Escaping from a room that was getting smaller and smaller made him think of something else he had seen in his collection: the Menger sponge—the cube that was made out of holes and had infinite surface area and zero volume. If you were inside it, every space you entered would be smaller than the one you had