"Nope! Chest was clean. What if I tell you there was extensive pinkish pulmonary edema, injected eyes, and sloughing of the tracheal epithelium."

"What's your presumptive diagnosis?" Laurie asked with a sigh.

Sometimes she found Jack's forensic guessing games tedious, and this was one of them.

"What if I told you our clever PA, Janice Jaeger, found a mixture of rather strong, open cleaning products in a glass-enclosed shower stall with a bucket of water and a damp cloth? Earlier, when she had viewed the body, she noticed the knees of the woman's jeans were wet, and the victim was not wearing any socks or shoes."

"I'd have to know if the cleaning products contained hypochlorite, which many do, and if others contained acid, which a lot do, and if she had ignored the warning not to mix them, and did."

"Bingo!" Jack said. "Chlorine gas, the first chemical-warfare agent used in World War One, did her in, not her boyfriend. It's amazing to me how many people blithely ignore product warnings. Anyway, Lou will be pleased it is not another homicide he has to worry about."

"Not unless the boyfriend was the one who insisted she use the deadly products, and use them together."

"Now that's a twist I hadn't even thought of," Jack admitted.

"Well, you boys enjoy yourselves," Laurie said, as she headed toward the exit. She felt no pleasure at having guessed the right answer to Jack's quiz. She would have been much happier if he were not in such a distractingly playful mood, whether real or feigned. It amazed and irritated her that he didn't see or was purposely ignoring the corollary between her case and his proposed surgery.

Instead of leaving Jeffries's specimens for the staff to bring up to the appropriate labs, as was the normal routine, Laurie took them herself. She wanted to talk to both the head of microbiology, Agnes Finn, and the head of histology, Maureen O'Connor, to try to move things along. But first she stopped on the first floor and went into the PA's office. Knowing they were often out in the field, Laurie was pleased to find Cheryl Myers still at her desk.

"Can I help you with something else?" Cheryl questioned. She was a striking African-American woman who wore her hair in tight, bead-encrusted cornrows. She was part of the old school at the OCME. In fact, she'd been working there long enough to put her two boys through college.

"I hope so," Laurie said. "Earlier, I was speaking with Dr. Besserman about some infection cases at three hospitals run by a company called Angels Healthcare. He said he asked you to look into it. Do you recall?"

"Are you talking about the MRSA pulmonary cases?"

"Those are the ones! Did you make a site visit?"

"No! What he asked me specifically was to obtain hospital records, so I merely called and spoke to the medical records department in each hospital. It was easy to get the charts, because Angels hospitals have their medical records computerized. The material was e-mailed over. I didn't need to make a visit."

"Were the hospitals cooperative?"

"Very cooperative. I even got an unsolicited call back from a very helpful woman by the name of Loraine Newman."

"Who is she?"

"She is the chairperson of the orthopedic hospital's infection-control committee."

"Dr. Besserman mentioned her," Laurie said. "He commented on how genial she was as well. Why did she call back?"

"Just to leave her name and direct-dial number in case I needed anything else. She said she was very concerned about the problem. She told me that prior to the MRSA outbreak, they'd had no nosocomial problems to speak of. She said the situation was keeping her awake at night. To tell you the truth, she sounded a little desperate."

"Did she mention a Cynthia Sarpoulus?"

"Not that I can recall. Who is she?"

"I've just posted another case of MRSA that came in from Angels Orthopedic Hospital," Laurie said, ignoring Cheryl's question. "I'd like Loraine Newman's phone number."

"Not a problem," Cheryl said. With a few clicks of her computer mouse, she had it on her screen.

"I need some other numbers," Laurie said. "The CDC in Atlanta has an MRSA program as part of its National Healthcare Safety Network. I'd like you to get me a name and phone number of one of its epidemiologists. I'd also like you to call the Joint Commission for Accreditation of Healthcare Organizations and get me a name and number for someone in surveillance of mandated hospital infectious-control programs."

"I'll do my best," Cheryl said.

"The name of my case is David Jeffries," Laurie continued. "I'd like his hospital record."

"That will be easy," Cheryl said. "But I'm not sure I understand who it is you want to talk to at the joint commission. Could you give me a better idea?"

"The joint commission requires hospitals to have infection-control committees for accreditation. What I want to find out is whether there is any policing of these committees and whether any reporting of outbreaks is required between formal inspections. I know this is a bit unusual," Laurie said, "but I'm pressed for time."

"I'm happy to help," Cheryl said good-naturedly.

Laurie left the forensic investigator's office and went to the stairs, avoiding the back elevator. She'd started the day with a selfish desire to talk Jack out of his imminent surgery. Now she was worried about his well-being, maybe even his life. Among herself, Besserman, and Southgate, there were seven cases of fatal MRSA necrotizing pneumonia within three months at three hospitals, one of which Jack was scheduled to enter, and all run by the same company. And worse yet, these cases were occurring despite what Besserman had described as aggressive infection-control measures. Although Laurie was the first to admit that she didn't know too much about epidemiology, she knew enough to wonder if there might be a lethal, unknowing MRSA carrier, like a kind of Typhoid Mary in the Angels Healthcare organization who was inadvertently spreading MRSA as he or she went from hospital to hospital in the course of his or her job. Laurie wanted a lot of information, and as stubborn as Jack was, she wanted it fast if she hoped to influence his mind-set.

The next stop was microbiology, which was part of the laboratory complex on the fourth floor. Laurie found the taciturn, sinewy microbiologist Agnes Finn in her small, windowless office. Of all the employees of the OCME, Agnes's appearance was the most stereotypic for working in a morgue from central casting's point of view. Her grayish-yellow coloring contributed; it was as if she never saw the light of day. Yet, of all the supervisors, Laurie found Agnes to be the most helpful by far, always willing to go out of her way. It was as if she had no life outside the OCME.

Laurie sat down and explained the situation, which elicited from Agnes a mini-lecture on MRSA, including everything Besserman had to say and then some. She explained in detail how staphylococcus was such a pluripotent microbe, and perhaps the most adaptive and successful human pathogen.

"When you think about it from the bacteria's point of view," Agnes said, "it is truly a superbug, capable of killing someone in a frightfully short time while the same strain is able to merely colonize an individual, usually just within the nares. This is a convenient location for the bacteria, because every time the carrier puts his or her finger in their nose, their fingers are contaminated from where it can be spread to the next person."

"Is there an estimate as to how many people are so colonized?"

"Absolutely. At any given time, a third of the world's population carries staph; that's about two billion people."

"Good Lord," Laurie said. "Are there many strains of MRSA besides the hospital-acquired and the community-acquired?"

"Very many," Agnes said. "And they are evolving all the time in people's noses and elsewhere, like moist skin surfaces, where they exchange genetic material."