Jerry is a rather mischievous twelve-year-old boy with a sarcastic mother, a nervous father, and a nasty cat called Bonkers. As soon as his family moves into this big, eerie house, they find a piano in the attic. Jerry is confused when he hears someone playing the piano upstairs one night. He goes up to investigate, and the music abruptly stops; although there's nobody else in the attic, the seat of the piano is warm -- as if somebody had just been sitting on it. Before Jerry can figure this out, he finds himself agreeing to take lessons, and his parents have the piano moved downstairs. This is when he meets Dr. Shreek, an enthusiastic instructor who looks oddly like Santa Claus. A joker at heart, Jerry is not completely serious about learning to play, and is put off by his teacher's passion -- particularly the hungry expression on his face whenever he looks at Jerry's hands.
Jerry continues to hear the piano playing in the family room at night, but his parents don't, and think he's only goofing around when he tries to tell them about it. Waking abruptly from a disturbing dream about playing so fast that he can't stop, Jerry hears the music yet again, and this time sees a hideous ghost at the piano. However, he still attends Dr. Shreek's musical school after just a few preliminary lessons at home, meeting a scary-looking robotic floor sweeper as well as the janitor Mr. Toggle, a mechanical genius who has built not only the sweeper but many other strange machines. After hearing some unsettling rumors about the school from one of his new friends, Jerry sees the ghost again. She tells him the rumors are true, before revealing that she has no hands.
Jerry is so freaked out that he insists on quitting the lessons. The next time he comes to the Shreek School, he tells Dr. Shreek that he's quitting. Shreek abruptly loses his mind, and Jerry runs away from him into the recital hall -- only to see row after row of pianos with identical instructors, all being played by pairs of disembodied hands. Jerry is rescued by Mr. Toggle, who reveals that Dr. Shreek is only a robot by shutting him down -- as well as all the instructors and hands. Then Toggle abruptly reveals that he's been using human hands to "make beautiful music" (119) and that he needs Jerry's hands as well. This time, however, Jerry is saved by ghosts of the victims of the school -- including the one he saw in his house -- who grab Toggle and take him away, never to be seen again.
Jerry quits piano lessons. His parents sell the old piano at home and buy a big screen TV in its place. At school, Jerry is growing to like softball though he isn't very good at bat. Since he is good on the field, everyone says he has good hands, like Dr. Shreek always said.