"And Jeremy's blood or whatever you need to match--it's fairly rare?"

"Yes."

Emily and Greg were both of Irish descent. Myron's family came from the usual potpourri of old Russia and Poland and even a little Palestine thrown in. Mixed blood. He thought about the paternity implications.

"So after you exhausted the family, how do you search for the match?"

"You go to the national registry."

"Where are they located?"

"In Washington. You listed?"

Myron nodded.

"They keep computer records there. We search for a preliminary match in their banks."

"Okay, now assuming you find a match in the computer--"

"A preliminary match," she corrected. "The local center calls the potential donor and asks them to come in. They run a battery of tests. But the odds of matching are still fairly slim."

Myron could see that Karen Singh was relaxing, comfortable with the familiar subject matter, which was exactly what he wanted. Interrogations are a funny thing. Sometimes you go for the full frontal attack, and sometimes you sidle up, friendly-like, and sneak in the back. Win put it simpler: Sometimes you get more ants with honey, but you should always pack a can of Raid.

"Let's suppose you find a full-fledged donor," Myron said. "What then?"

"The center acquires the donor's permission."

"When you say 'center,' do you mean the national registry in Washington?"

"No, I mean the local center. Do you have your donor card in your wallet?"

"Yes."

"Let me see it."

Myron took out his wallet, flipped through about a dozen supermarket discount cards, three video club memberships, a couple of those buy-a-hundred-coffees-get-ten-cents-off-the-hundredth coupon, that sort of thing. He found the donor card and handed it to her.

"See here," she said, pointing to the back. "Your local center is in East Orange, New Jersey."

"So if I was a preliminary match, the East Orange center would call me?"

"Yes."

"And if I ended up being a full match?"

"You'd sign some papers and donate marrow."

"Is that like donating blood?"

Karen Singh handed the card back to him and shifted again. "Harvesting bone marrow is a more invasive procedure."

Invasive. Every profession has its own buzzwords. "How so?"

"For one thing, you have to be put under."

"Anesthesia?"

"Yes."

"And then what do they do?"

"A doctor sticks a needle through the bone and sucks the marrow out with a syringe."

Myron said, "Eeuw."

"As I just explained, you're not awake during the procedure."

"Still," Myron said, "it sounds much more complicated than giving blood."

"It is," she said. "But the procedure is safe and relatively painless."

"But people must balk. I mean, most probably signed up the same way I did: They had a friend who was sick and ran a drive. For someone you know and care about, sure, you're willing to make a sacrifice. But for a stranger?"

Karen Singh's eyes found his and settled in hard. "You are saving a life, Mr. Bolitar. Think about that. How many opportunities do you get to save a fellow human being's life?"