What does Percy see at the fruit stand that scares him so much?

Percy saw the old woman snipping the yarn.

“You mean the old ladies? What is it about them, man? They’re not like … Mrs. Dodds, are they?”

His expression was hard to read, but I got the feeling that the fruit-stand ladies were something much, much worse than Mrs. Dodds.

He said, “Just tell me what you saw.”

“The middle one took out her scissors, and she cut the yarn.”

He closed his eyes and made a gesture with his fingers that might’ve been crossing himself, but it wasn’t. It was something else, something almost-older. He said, “You saw her snip the cord.”

“Yeah. So?”

But even as I said it, I knew it was a big deal.

“This is not happening,” Grover mumbled. He started chewing at his thumb. “I don’t want this to be like the last time.”

“What last time?”

“Always sixth grade. They never get past sixth.”

“Grover,” I said, because he was really starting to scare me. “What are you talking about?”

“Let me walk you home from the bus station. Promise me.” This seemed like a strange request to me, but I promised he could.

“Is this like a superstition or something?” I asked. No answer.

“Grover-that snipping of the yarn. Does that mean somebody is going to die?”

He looked at me mournfully, like he was already picking the kind of flowers I’d like best on my coffin.