"What do you mean by 'compromise'?" Laurie asked dubiously.

Jack fidgeted in his chair. It was apparent that he was uncomfortable with the question. Laurie let him take all the time he wanted. Finally, he made a gesture of confusion by hunching his shoulders and extending his free hand, palm up. "We'll agree to make sure we discuss the issues on a regular basis."

Laurie's heart sank. "That's no compromise," she said with a voice that reflected her discouragement. "Jack, we both know what the issues are. At this point, more talk is not going to solve anything. I know that sounds contrary to what I've usually said about the importance of communication. The fact of the matter is that I've been compromising from the beginning, and particularly over the last year. I think I understand where you are coming from, and I'm sympathetic, which is what has kept me in a circumstance that has not been satisfying my needs. It's really as simple as that. I believe we love each other, but we're at a crossroads. I'm not twenty-five anymore. I need a family; I need commitment. To use one of your expressions, the ball is in your court. It's your decision. Talk is superfluous at this point. I'm not going to try to convince you, which, at this stage, talk would begin to sound like. And one final point: I didn't leave in a moment of pique. It's been a long time coming."

For a few minutes, they merely stared at each other without moving. Finally, Laurie was the one who moved. She leaned forward and gave Jack's thigh a squeeze just above the knee. "This doesn't mean I don't want to talk in general," she said. "It doesn't mean we're not friends. It just means that unless we can truly compromise, I'll be better off staying at my apartment. And meanwhile, I'll get back to my diversion."

Laurie stood up, smiled down at Jack without rancor, and then walked back through the communications room en route to the elevator.

WITH A MIGHTY YAWN THAT brought tears to her eyes, Laurie put down her pencil, stretched, and then viewed her handiwork. She had created a matrix on a piece of graph paper that had the names of the four patients of her supposed series on the left-hand side of the page. Running along the top of the page and creating columns were all parameters of the cases that she thought might be important, including: the age of the patient, the sex of the patient, the type of surgery involved, the name of the surgeon, the anesthesiologist and anesthetic agent used, the sedative and pain medication employed, where in the hospital the patient was boarded, how the patient was discovered and by whom, the time the patient was discovered, who did the autopsy, any potentially relevant pathology, and the toxicology results.

Currently, Laurie had preliminary entries in all the boxes of her matrix, except for the names of the surgeons and anesthesiologists, the type of anesthetic and drugs used, the toxicology results on the two cases she had posted, and any possible relevant pathology on Darlene Morgan. To fill in the empty boxes, she needed the hospital charts and the continued cooperation of Peter and Maureen. In the toxicology boxes of the two cases posted by Kevin and George, Laurie had written: negative screen, further testing pending.

One piece of information that the matrix had already brought to her attention, which she thought important and mildly damning for her theory of a serial killer, was that the cases were not on the same ward. Two of the patients had been on the general surgical floor, while the other two had been on the orthopedic and neurosurgical floor. Since none of the patients had had neurosurgery and since one of the orthopedic cases had been on general surgery, Laurie had already called the Manhattan General admitting office for an explanation. The explanation turned out to be simple: Because the hospital operated at near capacity, beds frequently had to be allocated irrespective of the type of surgery.

From the moment Laurie had left Jack in the ID room, she had been a human dynamo in regard to investigating the four patients. Her motivation was twofold. There was the continued need for a diversion to keep from obsessing about her own problems, as Jack had surmised. That hadn't changed. What had changed was a strong desire to vindicate her intuitive belief that these cases did not represent a coincidence. Jack's blithe dismissal of the idea had been both belittling and galling.

First, she had gone up to histology to see Maureen, who'd been happy to present her with a tray of McGillan's HE-stained microscopic sections in less than twenty-four hours. With the burden of processing eight thousand autopsies a year, overnight histology-slide service was unheard-of. Laurie had thanked her profusely for her efforts and had immediately taken the slides back to her office to study them painstakingly. As she had suspected, she found no pathology in general, and specifically, she found the heart entirely normal. There were no signs of active or healed inflammation of the cardiac muscle or the coronary vessels, and she saw no abnormalities of the valves or conduction system.

Next, she had gone down to the fourth-floor toxicology lab, where she'd run into a minor setback by bumping into John DeVries. Thanks to the bad blood between them and John's territoriality, he'd demanded to know what she was doing wandering around in his laboratory. Not wishing to get Peter in trouble with his boss, Laurie had to be creative. She happened to have been standing next to the mass spectrometer, so she said she had never completely understood mass spectrometry and was hoping to learn something about it. Mollified to a degree, John had provided her with some printed literature before excusing himself to go down to the serology lab.

Laurie had found Peter in his windowless, Lilliputian office, and his eyes lit up when he saw her. Although Laurie didn't remember Peter from their life prior to the OCME, Peter remembered her when they both had attended Wesleyan University in the early eighties. He had been two years behind her.

"I ran a toxicology screen on McGillan," Peter had said. "I didn't find anything, but I have to warn you that sometimes compounds can hide out in the peaks and valleys on the readout, particularly when the concentration is very low. It would be a big help if you gave me more of a hint of what you are looking for."

"Fair enough," Laurie had said. "Since the autopsies on these patients suggested they suffered a very rapid demise, their hearts had to suddenly stop pumping blood. I mean, one minute everything was fine, and the next minute there was no circulation. That means we have to eliminate cardiac toxins like cocaine and digitalis, and any other drugs that can cause changes in the heart rate, either by affecting the center that initiates the beat or the conduction system that spreads the impulse around the heart. On top of that, we even have to rule out all the drugs that are used to treat abnormal cardiac rhythms."

"Wow! That's a rather big list," Peter had commented. "The cocaine and the digitalis I would have seen, because I know where to look on the readout, and they'd have to be big doses to do what you are talking about. The others, I don't know, but I'll look into it."

At that point, Laurie had asked about Solomon Moskowitz and Antonio Nogueira, whose autopsies had been done several weeks earlier. She told Peter that the cases mirrored McGillan's. Using his keypad in front of his monitor and his password, Peter accessed the laboratory database. Both toxicology screens had been normal, but he offered to run them again now that he had a ballpark idea of what she was looking for.

"One other thing," Laurie had said when she was about to leave. "I did another case this morning whose samples should be on the way up. Again, it was strikingly similar to the others, which tells me there's something weird going on over at the Manhattan General. Since I can't find any pathology, I'm afraid the major burden is going to be on your shoulders to find out what it is."