I thought that over for a minute and said, “Because she was doing something she didn’t want you to know about, something that would have given you the whip hand if you’d found out about it. That’s where we’ll start our investigation.”

I caught a note of quick hope in Mrs. Alftmont’s voice. She said, “Charles, I believe he s right.”

Alftmont said, “I can believe anything of her. She became selfish, neurotic. Her ego demanded flattery. She was never happy unless some man was paying attention to her. She wanted to be on the go all the time. She was apparently trying to escape any form of routine, any conventional—”

“I know the type,” I said. “Never mind putting it in medical terms.”

“She is selfish, tricky, deceitful, and unbalanced,” he said. “You can expect anything of her. Once she starts, she won’t stop anywhere.”

I got to my feet and said, “I’m taking these letters. Is there a night train through here for San Francisco?”

“None now,” he said.

“How about a bus?” I asked.

“I think there’s a bus goes through.”

“I’ve had about all the night driving I want for a while,” I said. “I’m taking these letters with me.”