"How are the strains differentiated in the laboratory?"

"Many ways," Agnes said. "Antibiotic resistance is one."

"But that's not particularly sensitive, considering everything you've said."

"That's correct. The more sensitive methods are all genetics-based: the simplest and most commonly employed being pulse-field gel electrophoresis, and the most complete being full genotyping. In between, there are a number of other sequence typing techniques all based on PCR."

"What can you do here in microbiology?"

"Only the simplest: antibiotic resistance."

"If needed, where can the more complicated be done?"

"The state reference lab can do the pulse-field gel electrophoresis. As for more specific typing, the CDC is the best bet. They are actually building a national library of MRSA strains, so they can give you a lot of information. They encourage submissions of isolates, and they can do it all. Of course Dr. Lynch in our DNA lab over in the new high-rise can do the various genetic typing, but we won't be able to tell you much about the specific strain."

"Which of the genetic tests is the fastest? I'm up against a time constraint."

"Truthfully, I don't know. What I do know is that our standard culture and antibiotic sensitives take twenty-four to forty-eight hours. Hospitals can do it much faster using monoclonal antibody-based methods. Interesting enough, such machines came out of work for NASA."

Laurie shook her head. She was humbled. "Before today I thought I knew a reasonable amount about staph. But I was sorely mistaken."

"We all have to keep learning," Agnes said philosophically. "What do you want to do about these specimens you've brought in?"

"I'll take one over to Ted Lynch in the DNA lab. I'd like one for you to culture, and the rest can go to the reference lab. I'm also going to want to get some frozen samples from some of Dr. Besserman's and Dr. Southgate's cases to compare. I'd like to know if they are from the same strain. I'm concerned about an unsuspecting carrier, particularly after what you've told me."

"Let me know the cases you are interested in. I'll try to expedite the process. As for Ted Lynch, you'll have to leave it to me to provide him with a pure culture for his DNA analysis."

With her head in whirl, Laurie hurried out of the lab and headed toward the faster front elevator. As she hit the up button repeatedly, in vain hope of speeding up the elevator's arrival, she tried to plot the course of the rest of her morning. The first stop was going to be Maureen O'Connor in the histology lab, where Laurie intended to beg for David Jeffries's lung sections to be processed into slides as quickly as possible; Laurie didn't care about the rest of the slides at the moment, just the lung, since she had in mind to make some large photomicrographs if the pathology appeared as bad as she fully expected it would. She thought they would make terrific PowerPoints for the argument she intended to wage against Jack to get him to cancel his ACL repair.

Laurie boarded the elevator and pushed the button for the fifth floor. She looked at her watch. It was close to ten. Exiting, she literally ran down the hall into histology and arrived mildly out of breath.

"Uh-oh! Ladies," Maureen scoffed in her heavy brogue, "I seem to sense another acute emergency from Miss Montgomery. Errr… that's Mrs. Montgomery-Stapleton. Who'll volunteer to tell her this time, her patient is already dead?"

There was general laughter from the women who worked in histology. Thanks to Maureen's good humor, it was a happy environment. Even Laurie found herself smiling despite her anxiousness. Like most humor, there was truth in Maureen's comment. Laurie and Jack were the only pathologists on the ME staff who, on occasion, felt they needed a rapid turnover with their microscope slides. All the others were content to have them in due course.

Maureen listened to Laurie's request and explanation, and promised to do them herself. Within minutes, Laurie was back in the hall. She hurried down to Arnold Besserman and Kevin Southgate's office. As she knocked, the door swung open on its own, and Laurie leaned inside.

The interior of the office reminded Laurie of the two men's polar political leanings. As the archconservative, Arnold had a desk that was the picture of neatness, with a single cardboard tray of slides on one side of his microscope and a new yellow legal pad on the other. Both were aligned perfectly parallel to each other along with a precisely sharpened pencil. Southgate's side of the room was the opposite, with slide trays, unfinished case files, lab reports, and all manner of other documents piled on both his desk and file cabinet, leaving only a small arc of cleared horizontal space directly in front of his chair. A vast clutter of Post-it notes hung from the shade of his desk lamp like so much Spanish moss. It was a wonder to Laurie how the two men got along so well and for so long.

After leaving a note on the door for either man to call her, Laurie went down the hall, knocking at the other medical examiners' doors to do a quick survey of their recent MRSA experience. No one was in his office, which was entirely understandable, since the morning was the busy time in the pit, although she'd not seen George Fontworth, Paul Plodget, or his newly hired office mate, Edward Gonzales. Edward was a gifted forensic pathologist who was a product of OCME's own program and New York University.

Momentarily thwarted in scaring up more MRSA cases at the OCME, Laurie retreated to her own office. Suddenly, remembering Arnold Besserman's comment about Queens, Brooklyn, and Staten Island, all of which had their own ME offices, she realized her conclusion that there had been no fatal MRSA cases in any of the other city hospitals during the last three months or so was premature.

With her Rolodex open, Laurie first called Dick Katzenburg, the chief of the Queens office. He'd helped Laurie in the past by coming up with cases that matched the two series of cases she had become deeply involved with. As the call went through, Laurie recalled that both those previous series of hers had surprisingly turned out to be homicides, which no one suspected, even she. The remembrance briefly stimulated the thought that the manner of death of her current series might not be accidental, especially considering that a third of the world's population was colonized with staph organisms at any given time.

The Queens ME office answered, and Laurie asked for Dick. While she waited, she tapped her fingers nervously. She hoped he'd be available, which she thought was a reasonable expectation. In his role as chief of the satellite office, administrative duties often kept him at his desk and out of the autopsy room. As the time dragged on, she got out a fresh legal pad, and with the phone in the crook of her neck, she drew multiple vertical parallel lines, creating a checkerboard matrix in which she planned to add information about the MRSA cases as she learned it. With her two previous series, it had been the matrixes that had given her the insight she'd needed. Hoping for a similar outcome, she wrote David Jeffries on the top row, to the left of the indent line.

Dick came on the line apologetic for keeping her waiting. After a bit of social chatter, Laurie asked if they had seen in the Queens office any MRSA nosocomial infections over the last three or even four months.

"We have indeed!" Dick said without hesitation. "They weren't my cases; they were Thomas Asher's. I remember them because they were fairly ugly."

"Meaning?"

"Necrotizing pneumonia. The victims, who were all healthy people, didn't have a chance. Their histories reminded me of the stories of the influenza epidemic in 1918."

On the spur of the moment, Laurie felt a pang of selfish disappointment. The fact that other hospitals in the city were experiencing the same problem as the Angels Healthcare institutions would undoubtedly dilute the cases' impact on Jack.