Finally, after Molly had put Amanda to bed, they sat at the dining-room table, sipping coffee. Molly, growing concerned by Pierre’s quiet, said, “A penny for your thoughts.”

“I thought you could take them for free,” said Pierre, a little sharply. His expression showed that he immediately regretted it. “I’m sorry, sweetheart. Forgive me. I’m just angry.”

“About… ?”

“Well, Felix Sousa, of course — which got me to thinking about that paper he and Klimus did a few years ago for Science on reproductive technologies. Anyway, thinking about that paper got me thinking about Condor Health Insurance — you know, this business of financially coercing the abortion of imperfect fetuses.” He paused. “If I wasn’t already manifesting symptoms of Huntington’s, I’d cancel my policy in protest.”

Molly made a sympathetic face. “I’m sorry.”

“And that stupid letter Condor sent me — what patronizing crap, from some flack in the PR department. A complete brush-off.”

Molly took a sip of coffee. “Well, there’s one way to get a little more attention. Become a stockholder in Condor. Companies are usually more responsive to their stockholders’ complaints because they know that if they aren’t, the questions might be raised in person at their shareholders’ meetings. I took a course in ethics back at UM; that’s one of the things the prof said.”

“But I don’t want to support a company like that.”

“Well, you wouldn’t invest a lot.”

“You mean buy just one share?”

Molly laughed. “I can see you don’t play the markets much. Shares are normally bought and sold in multiples of a hundred.”

“Oh.”

“I take it you don’t have a broker, right?”

Pierre shook his head.

“You can call mine: Laurie Lee at Davis Adair. She’s great at explaining things.”

Pierre looked at her, startled. “You really think I should do this?”

“Sure. It’ll increase your clout.”

“What would a hundred shares cost?”

“That’s a good question,” said Molly. She headed down to the den, and Pierre followed her, holding carefully to the banister to help keep his balance on the short flight of stairs. Sitting on a desk was a Dell Pentium computer. Molly booted it up, logged on to CompuServe, scurried down a couple of layers of menus, and pointed to the screen. “Condor closed today at eleven and three-eights per share.”

“So a hundred shares would cost — what? — eleven hundred and… and…”

“Eleven hundred and thirty-seven dollars and fifty cents, plus commission.”

“That’s a fair piece of change,” said Pierre.

Molly nodded. “I suppose, but it’ll all be liquid. You should be able to recover almost all of it, if you decide to sell later on. In fact…” She tapped some more keys. “Look at that,” she said, pointing at the table that appeared on screen. “They’ve been climbing steadily. They were at just eight and seven-eighths this time last year.”

Pierre made an impressed face.

“So we might even end up making money when you eventually sell the stock. But, for the time being at least, Condor will have to take you seriously.”

Pierre nodded slowly, thinking it over. “Okay,” he said at last. “Let’s do it. How do I proceed?”

Molly reached for the phone. “First, we call my broker.”

Pierre pointed at the clock. “Surely she won’t be in this late.”

Molly smiled indulgently. “It may be eight p.m. here, but it’s noon in Tokyo. Laurie has a lot of clients who like to play the Nikkei. She could very well still be in.” Molly touched a speed-dial key. She was obviously very much into this; she had mentioned her investments in the past, but Pierre had never quite realized just how conversant she was with the field.

“Hello,” she said into the handset. “Laurie Lee, please.” A pause. “Hi, Laurie. It’s Molly Bond. Fine, thanks. No, not for me — for my husband. I told him you were the best in the business.” Laughter. “That’s right; anyway, can you take care of him, please? Thanks. His name is Pierre Tardivel; here he is.”

She held the handset out for Pierre. He hesitated for a moment, then brought it to his ear. “Hello, Ms. Lee.”

Her voice was high-pitched, but not grating. “Hello, Pierre. What can I do for you?”

“Well, I’d like to set up an account so that I can buy some stock.”

“Very good, very good. Let me just get a few personal details…”

She asked for information about his employer, and for his Social Security number (which Pierre had to consult his wallet to determine, having only recently received it).

“Okay,” said Laurie. “You’re all set. Was there anything you wanted me to buy for you now?”

Pierre swallowed. “Yes. A hundred shares of Condor Health Insurance, please.”

“They’re on the California Stock Exchange; I won’t be able to place the order until tomorrow. But as soon as the exchange opens, I’ll get you one hundred C-H-I Class B.” Pierre could hear keyclicks. “You know, that’s an excellent choice, Pierre. A very excellent choice. Not only has that stock been doing well on its own — it’s very close to its all-time high, which was set just two weeks ago — but it’s also done significantly better than its competition in the past year. I’ll send you confirmation of the purchase in the mail.”

Pierre thanked her and hung up, feeling quite the entrepreneur.

Three weeks later, Pierre was working in his lab. The phone rang. “Allo?”

“Hi, Pierre. It’s Helen Kawabata at the SFPD.”

“Helen, hi! I’d been wondering what had become of you.”

“Sony, but we’ve been swamped by that serial-killer case. Anyway, I’ve finally got together some tissue samples for you.”

“Thank you! How many did you get?”

“A hundred and seventeen—”

“That’s terrific!”

“Well, they’re not all from SF; my lab does forensics work on a contract basis for some of the surrounding communities, as well. And some of the samples are several years old.”

“But they’re all unsolved murders?”

“That’s right.”

“That’s great, Helen. Thanks so much! When can I come and get them?”

“Oh, whenever—”

“I’m on my way.”

Pierre picked up the samples, brought them back to LBNL, and turned them over to Shari Cohen and five other grad students; there were always plenty around. Through the polymerase chain reaction, the students would produce copies of each set of DNA, then test the material for thirty-five different major genetic disorders Pierre had specified.

That evening, as he was leaving building 74, Pierre passed Klimus in a corridor. He responded to Klimus’s curt “Good night” with a soft “Auf Wiedersehen,” but the old man didn’t seem to hear.

While he waited for the grad students to report back on the samples Helen Kawabata had provided, Pierre mapped out all the cytosines in the portion of Molly’s DNA that contained the code for the telepathy neurotransmitter. He then crunched the numbers backward and forward, looking for a pattern. He’d wanted to crack the hypothesized code that cytosine methylation represented, and he could think of no more interesting stretch of DNA to work on than that part of Molly’s chromosome thirteen.

And at last he succeeded.

It was incredible. But if he could verify it, if he could prove it empirically—$

It would change everything.

According to his model, cytosine-methylation states provided a checksum — a mathematical test for whether the string of DNA had been copied exactly. It tolerated errors in some parts of the DNA strand (although those errors tended to render the DNA garbled and useless, anyway), but in others — notably right around the telepathy frameshift — it would allow no errors, invoking some sort of enzymatic correction mechanism as soon as copying was initiated. The cytosine-methylation checksum served almost as a guardian. The code to synthesize the special neurotransmitter was there, all right, but it was deactivated, and almost any attempt to activate it was reversed the first time the DNA was copied.