"Reds are prime numbers?"

"Right. I just keep putting numbers in and when I get bored with entering them, I go back, multiply by twos, and make them black."

"There's a nine thing I learned when I had a summer job at a bank," Jane said. "Any number

like…" She punched in multiplication in the little adding machine beside him. Nine times eighty-three. It came up seven hundred forty-seven.

"See? The two sevens equal fourteen and with the four they equal eighteen, which is divisible by nine. It's always that way."

"Cool! How'd you know that?"

"My dinky job at a bank one summer during high school was checking tapes of wads of checks. They were always added twice. When they didn't add up exactly, this wise old woman, who'd started at the bank doing the same boring job when she was my age, told me that if the difference in the two tapes equaled something divisible by nine, at least one number on a tape had been transposed."

"Transposed?"

"Yes, like sixty-three for thirty-six. It made it easier to find the error. So I played around with nines and discovered how neat they are. You want to shower first?"

"Okay. I'll leave you some hot water."

Todd saved his grid, shut down his computer, and headed for the kids' bathroom before Katie could pull herself together and occupy it for half an hour.

Jane went downstairs, made peanut-butter-and-jelly sandwiches, and got out little plastic containers of orange juice for Todd's and Katie's traveling-to-school breakfasts. Then she hotfooted it back upstairs to work on her house

plans. Two hours later, she realized that the house was quiet except for Willard barking at the back door to be let out.

It had seemed mere minutes since she'd sat down at the computer. This could be dangerous, she thought. Time just flies away when I'm doing this.