“But she says on her birthday.”

“Well, when is her birthday?”

“Can’t you understand?” said Bobbie. “I’ve forgotten.”

“Forgotten!” I said.

“Yes,” said Bobbie. “Forgotten.”

“How do you mean, forgotten?” I said. “Forgotten whether it’s the twentieth or the twenty-first, or what? How near do you get to it?”

“I know it came somewhere between the first of January and the thirty-first of December. That’s how near I get to it.”

“Think.”

“Think? What’s the use of saying ‘Think’? Think I haven’t thought? I’ve been knocking sparks out of my brain ever since I opened that letter.”

“And you can’t remember?”