"It's a simple idea," Mrs. Xin said over tea. "Anyone can create a course. You can pick your materials lesson by lesson, or you can just upload a book. Once you do that, anyone else can see and use your course. If enough people use it, Hypnologis pays you, and you get famous." The company's name didn't translate well—Mrs. Xin rendered it more or less as "dream word teach." But Tubby knew what she meant. She had read those characters a lot by now.

"What if you want to take a secret course?"

Mrs. Xin shook her head. "You can't. Everyone's activity and materials are public."

"One of their nerd users must have figured out how."

Mrs. Xin shrugged.

"But if you logged into the network all the time and didn't seem like you were taking a course, that would be suspicious, right?"

Mrs. Xin shrugged again.

"So what would you do?"

"I suppose I'd add a normal course," said Mrs. Xin.

"You said math was harder than programming."

Mrs. Xin frowned; then her mouth opened in understanding. "Oh, I see. You'd add an easy course. So you could spend most of your effort on the secret course." Her expression changed. "Tubby—Taisheng, Mandarin—"

"Dr. Ramachandran works for Taisheng's company," she said. "They're working on the Europa cells. He's supposedly learning Tamil."

Mrs. Xin steepled her fingers and pressed them to her lips. "Tubby," she said, "Vikas and Taisheng could get in a lot of trouble."

Tubby snorted. "Vikas, is it?"

"He's very sweet," said Mrs. Xin. "And so much more stamina than Dr. Gaynor, I can't even tell you—"

"Don't!"

"I'm worried," said Mrs. Xin. "He's not dealing well with his problem. He's very agitated."

"He's not the only one," said Tubby, slumping back in her chair. When Mrs. Xin asked her what she meant, she did not say. She was not ready to say it yet. Her back hurt; she closed her eyes.