Three laps around the block later, Lulu was back in her own kitchen eating a hideous, horrible bean-and-beet omelet. She was also still plotting how to get rid of Ms. Sonia Sofia Solinsky, who wasn’t sounding that easy to get rid of.

“It’s almost time for my trombone lesson,” Lulu told Ms. Solinsky. “It’s just a few blocks away. I can go by myself.”

“You won’t be going anywhere by yourself,” said Ms. Solinsky. “I promised your folks I’d watch over you, and I will. And since this morning’s escapade, I will be watching over you very carefully.” She then explained what “very carefully” meant:

“It means that I will be going with you to your trombone lesson today and to the front door of your school to drop you off and pick you up every day next week, as well as to the bathroom every night when you take a bath, as well as to your dog-walking job on Monday, Tuesday, Wednesday, Thursday, and Friday. Any questions?”

“Yes, sir,” said Lulu. “Will you also be going along with me when I throw up your delicious bean-and-beet omelet?”

“I am not amused,” said Ms. Solinsky.

“Me either,” Lulu said to her, heading out the door with her trombone and—of course!—Ms. Solinsky. And shortly thereafter the two of them were standing outside the house of—I’ll explain this to you in a second—Harry Potter.