Finally! The last member of the Old Guard present and accounted for. I could check the last suspect off my list. Minutes before his scheduled performance, Ledbetter entered the packed seminar room and sat down at the faculty table. He gazed proudly over the audience and showed no sign of pre-seminar anxiety. He seemed energetic and physically fit for a guy over 50, although he sat with a slouch. Was it an expression of arrogance or the result of too much desk work?

     Advanced-stage male-pattern baldness. A detractor might say he looked like a bald man with two large fuzzy ear muffs made of short dark hair. But I attributed it to male vigor — a surplus of androgen in his blood — and perhaps too many decades of high-voltage mental activity.

     Dr. Mary Pennington glanced from the clock, to the audience, to Ledbetter, as if wanting to be told when to start. He nodded, and she went to the lectern.

     "I am sorry to say that it will not be possible for me to give Dr. Ledbetter an adequate introduction, because then there wouldn’t be any time left for his seminar." Her delivery bordered on sassiness. "Dr. Ledbetter received his Ph.D. in Physiology at Yale University in nineteen sixty-nine. From there he went to the Max-Planck Institute for Physiology in Frankfurt, Germany."

     Dr. Ledbetter listened to her recitation with a patient but bemused expression.

     "After three years, he took a position in this department, where he has been ever since. He has numerous papers, including a patent for selectins as diagnostic devices."

     Dr. Ledbetter made an infinitesimal movement to get up, which caused Pennington to cut herself short and sit down. Ledbetter walked up to the lectern, stood beside it, surveyed the audience and launched smoothly into a terminology-packed introductory sentence that blew us all away.

     "The topic of my research is ‘lymphocytic selectins.’ As many of you know, the selectins are a class of adhesion or ‘integrin’ molecules, which are cytoskeletally attached membrane glycoproteins, which give specificity to the interaction of lymphocytes with the cells of the tissue in which the integrin is located."

     Whew!

     "Some of you will remember that it was the research conducted in my laboratory that showed a tissue specificity among the selectins. This is the probable basis for lymphocyte homing."

     I understood only 10 percent of it. He delivered this extremely technical introduction fluently and flawlessly, all the time bathing the audience in the aura of a supercilious smile. To my taste, his bragging was thinly disguised and overdone. Scientists have an odd way of bragging. You’re not allowed to say that you discovered the cure to cancer, but it’s permissible to say the cure was discovered "in your laboratory." You are not allowed to say that your work is important, but you are allowed to say that it is properly considered a central reference point for everything in the Universe — as long as you mention the elements of the Universe one at a time, and do not use the word "Universe."

     So Dr. Ledbetter had just told us his work was the hottest stuff since the Big Bang and that his laboratory was the center of the Universe.

     Ledbetter was figuring out how the white blood cells know where to crawl around in the body. The cells in every tissue are coated with a type of "glycoprotein" — proteins with sugar molecules attached — called "selectin receptors." These receptors give white blood cells a toehold when they crawl around in the tissue, looking for bacteria to kill. And the "toes" on the white cells are called "selectins."

     Ledbetter told us that different white cells "go home" to different tissues. For a white cell, home is where it can get a toehold. White cells that go home to the liver have selectin toes which make a specially good fit with selectin receptor toeholds in the liver. White cells that go home to the spleen have selectin toes which work especially well in the spleen. If you take white cells out of the spleen and inject them back into the blood, they will return to the spleen — because that’s where they can get a toehold.

     "So what would a right-thinking scientist do with this knowledge?" Dr. Ledbetter asked rhetorically. "Well, if he were only a basic scientist, he might work away on some small aspect of the problem for the rest of his career. But if he were a true biomedical scientist, he would ask himself what is the most obvious medical application."

     Ledbetter said this with a thinly-disguised sneer. Authoritarian and critical, he practically told us that he couldn’t stand fools.

     "The question one should ask is how can we make this homing mechanism do useful work — or at least deliver useful information."

     He told how white cells flow in the blood along with the red cells. But when the white cells get activated, they put molecules on their surfaces which make them "sticky" so that they roll along the walls of the small arteries and veins. The walls of the small veins have "manholes" leading into the tissues. The manholes are too small for the red cells but certain white cells can sit on the manholes and squeeze themselves in — like Plastic Man squeezing himself under a door. Special selectin receptor molecules line the manhole and they "tell" the white cell if it has found the right hole. So white cells destined for the liver will crawl into the manholes in the liver. The same for muscle, skin and many other tissues. Once a white cell crawls through the manhole, it can crawl deep into the tissue to fight infection.

     Fascinating stuff, I thought. Molecules don’t have any minds of their own. They just bind when it feels right. But cells are smart machines, capable of making some decisions.

     Ledbetter’s self-described "contribution to medical science" was both brilliant and simple. He took the selectin molecules out of white cells, purified them, and made them radioactive. Then he put them back into the blood stream. The liver selectin molecules went to the liver. Spleen selectin molecules went to the spleen. Of course the radioactivity went where the selectins went, since it was firmly attached.

     Ledbetter showed us radioactivity pictures of the liver in living animals, visualized by the gamma rays from injected selectins which accumulated in the liver. Then he showed us how the picture was changed in hepatitis, liver cancer and in cirrhosis of the liver. The pictures were taken by an instrument called a "gamma camera" which can be found in every major hospital. Ledbetter made it clear that his imaging technique was destined for widespread use as a medical diagnostic technique.

     It was a fascinating presentation of clever experimental work, underpinned by mathematical analysis, driven by medical need and productive of medical application. Masterful! But Ledbetter’s presentation was marred by his condescending and sometimes sneering delivery. Like when he started talking about medical applications:

     "As many people realize, and as our deceased chairman was never tired of mentioning, biomedical research is an expensive proposition. Someone has to come up with a success now and then to justify the expense of keeping everyone busy. This is not to imply that those who have the power to administer the available funds are those who are the most productive in generating truly useful knowledge, or even recognizing it in its nascent stage. But then, it is heartwarming when something done in one’s department proves to have true medical value."

     These individually innocuous but cunningly packaged words brought pained expressions to the faces of many of the younger faculty. It was a most extraordinary statement, telling everyone that he, Ledbetter, was the only one who had any medical application and that the deceased chairman had squandered departmental money on medically irrelevant work.

     Dr. Ledbetter ended his seminar at precisely five minutes before the hour, leaving what he "hoped would be ample time for discussion of the material."

     At first no one had any questions. Ledbetter looked to my fellow student, Grant Shipley.

     "I think you wanted to ask a question during the seminar."

     "I . . . I just wanted to know if there were selectin receptors in the intestine."

     Ledbetter thought for a few seconds before answering. "It is a good question that I cannot answer at this time."

     Everyone looked around, wondering who would volunteer a question.

     "Are you going to use the proceeds of your patent for a villa in Monte Carlo or a mansion in Palm Beach?" asked Dr. Manson, stroking his beard and staring at his sandaled foot.

     "I will buy neither. I will build an adobe hut in Arizona and grow peyote in my rock garden."

     Some thought this was very funny, some did not.

     "I should not need to remind you, Dr. Manson, that the commercialization of a medical invention is a long, arduous process."

     The next person to venture a question was Dr. Pang Wong.

     "Does the selectin-lectin specific accumulation of neutrophils in a tissue depend on actin and myosin contractile activity?"

     On the face of it, the question sounded halfway intelligent. But Dr. Ledbetter didn’t want to hear anything from Dr. Cooper’s protégé.

     "Of course it depends on actinomyosin mediated contractile activity! The cells have to change shape to get through the post-capillary portals. They have to crawl in the tissue, so they have to use actomyosin to locomote. But that’s not the point. The point is that it is the selectins which provide the true selectivity that guides the process. Otherwise, the cells would wander around aimlessly, mindlessly and unproductively."

     A straightforward scientific answer with a carefully crafted, hidden meaning — telling Wong, to his face, that his research was aimless, mindless and unproductive. And lest anyone fail to perceive his hidden meaning, Ledbetter delivered his answer with a scowl that would blister paint off the wall.

     The next member of the audience to put himself at risk was Grant Johnson. Removing his glasses and staring at the soldered joint, he said, "I may have asked this question before, but what t’ heck."

     "Yes, you did. But what the heck?" Ledbetter was playful this time. He actually seemed to be enjoying himself.

     "Okay, then. What’s my question?" asked Johnson.

     "If you can use your laser."

     Hearty laughter erupted and was sustained by the built-up pressure of the seminar.

     "Well, can I use my laser, then?" persisted Johnson, unabashed.

     "Yes, we can. We just have to find a tissue in a living animal in which we have an optical path into a small blood vessel. Perhaps the Clark chamber in the rabbit ear would work. I would like to see neutrophils rolling in the arterioles. I would like to learn whether this is influenced by intracellular calcium, which you can so ably control and measure."

     "Then why don’t you come over and do it with me?"

     "Because it would be a major undertaking, and I have no experience with the Clark chamber. Perhaps one of the uncommitted graduate students might be interested."

     As Ledbetter talked about the problem, he warmed to Johnson and to the audience. As he got to the point of recommending it to the grad students, he seemed absolutely benevolent. What a bipolar personality! A snarling attack dog one moment; friendly beagle an instant later. Did this strong discrimination come from his scientific standards, or was there something less objective and more emotional behind it?

     Robert Gunnison had his hand in the air. After getting Ledbetter’s attention, Gunnison returned his gaze to the table at which he was sitting, staring as if at some unseen object a couple of feet below the surface.

     "I’m sorry . . . but I’m somewhat confused — "

     "As you quite often are," interjected Ledbetter.

     The audience could produce so many types of laughter. This time it was mildly derisive. I wasn’t the only one who was irritated by Gunnison’s pomposity.

     "That may well be," Gunnison continued, not elevating his gaze above the surface of the table, "but I am confused as to whether the tissue selectivity of the neutrophil specificity is under hormonal control."

     The question was a natural for Gunnison, since he worked on hormones. Ledbetter made a show of yawning. Then he shook his head and clicked his tongue.

     "You shouldn’t be confused, because I didn’t say anything about hormonal control of neutrophils."

     Gunnison squirmed.

     "Then, perhaps, I should have said that I would have liked to have known what influence hormones have on the tissue-specific neutrophil homing phenomenon."

     Typical Gunnison — unnecessarily complicated grammatical constructions describing nothing. But he didn’t sound so pompous this time. He sounded like a croaking teenager. The force of Ledbetter’s personality had flailed away his sophomoric, mature-beyond-his-years veneer.

     "Dr. Gunnison, the primary phenomenon is not hormone dependent. Of course, it is well known that the immune system can be up- and down-regulated by hormonal status. We even teach that to our medical sophomores. Perhaps it is I who should be confused as to whether you have even articulated a question."

     With a broad smile, Ledbetter had just told everyone that Gunnison wasn't even up to the level of a sophomore medical student. Ashton was smiling, obviously enjoying himself immensely.

     "Well, is the tissue specificity of the neutrophils changed with hormones?" Gunnison asked meekly, hoping to salvage something.

     "Categorically, no."

     "Thank you," said Gunnison, shaking his head and looking away.

     Dr. Kozinski’s hand went in the air. Would Ledbetter mistreat a mensch?

     "My question is quite specific: Does genistein inhibit the homing behavior?"

     "An excellent question, directed at whether tyrosine phosphorylation plays a role in exposure of selectin receptors in the tissue or affects selectin density on lymphocyte membranes. The answer is ‘yes’ on both counts, although we can apply genistein only to tissue culture. It is too toxic to do meaningful experiments with living animals."

     Just like Westley. Push a button and get a mini-dissertation! Dr. Ledbetter was once more benevolent as he delivered this highly technical information. Dr. Kozinski nodded back.

     Dr. Gordon Taylor had been listening to the exchange carefully and seemed to be nodding in approval. Peter Moore blurted out, "What was the ‘alpha constant’ and volume of distribution when you injected the gamma-radionuclide labelled lymphocytes back into the animal?"

     Dr. Moore was an expert at pharmacokinetic jargon.

     "Lymphocytes don’t behave like simple drugs. It’s not a simple case of alpha redistribution and a beta phase elimination. If pressed, I’d have to say we have a ‘bravo’ phase when the lymphocytes go rolling along, a ‘charlie’ phase when they dig into the tissues, and then a ‘delta’ phase when the specific ones return to the lymph."

     A forthcoming answer, but Ledbetter had put spin on it, making it sound like a military skirmish on the Mekong Delta. "Bravo" and "Charlie" are military terms; scientists would use the Greek letters "beta" and "gamma." For his part, Moore didn’t bat an eyelid and seemed to be quite satisfied with the answer. He thanked Dr. Ledbetter and turned his head slowly to Dr. Mary Pennington. As if on cue, she stood up and turned to the audience.

     "All of us are either completely informed or completely overwhelmed."

     Way to go, Pennington!

     "There being no further questions, we can now consider the seminar to be adjourned."

     Quite a performance! In fact, if Ledbetter’s selectin system had any lethal possibilities, I might have suspected him more than Ashton. The seminar was a natural topic for lunchtime conversation with McGregor.

     "Well, Rob. I guess Ledbetter didn’t like Cooper very much."

     "So you picked up on that, did you?"

     "But, Rob, he practically spelled it out to everyone."

     "Yeah. Cooper had this funny thing about money. He couldn’t get enough of it. Ledbetter got some commercial sponsorship of his patent. According to University policy, half of the royalties should have gone to Ledbetter as a bonus. But when Cooper got wind of it, he forced Ledbetter to pay a bigger fraction of his base salary. This freed up an equivalent amount of Departmental hard money. And what did Cooper use it for? He raised his own salary. Ledbetter was pissed to the gills."

     "You mean Ledbetter’s medical diagnostic invention brought in some money, and Cooper celebrated it by squeezing Ledbetter and paying himself a raise?"

     "Yeah. And the two fought like cats and dogs. They were firing confidential memos at each other for over a year. Of course, what really set off the shooting match was what Cooper did to Mrs. Epstein. Ledbetter’s shaken up lots of people around here, but when it comes to old ladies he’s a real gentleman. And he almost succeeded in getting Cooper tossed out over the Epstein issue and the finance irregularities. He would have succeeded if the Dean hadn’t stood up for Cooper and told Ledbetter to back off. Boy, was Ledbetter pissed!"

     "Doesn’t sound like a very conscientious dean."

     "No, the guy’s just interested in control. This joint works on rhetoric, broken promises and ‘funny money.’ But what do you expect for a place called Bryan Medical School? It’s named after William Jennings Bryan. Check your local history and you’ll learn it was his loud mouth that got Opa Locka University started in the first place. The medical school thrives, operating by his methods.

     McGregor tucked his thumbs in his armpits in a parody of a crackerbarrel orator.

     "They say you can drive an ambulance through one of the Dean’s speeches without scraping a fact," he said, in an accent as broad as the Great Plains.

     "What was going on between Ledbetter and Manson today?"

     "Manson doesn’t like Ledbetter telling everyone his work is medically relevant. Ledbetter doesn’t like to be reminded how Cooper grabbed his royalties. But Manson had it coming."

     "I wonder about Manson."

     "Yeah, the guy’s crazy, all right. Once he had a prolonged brain-fade in front of a whole class of medical sophomores while he was lecturing on anesthetic gases. The medical sophomores started a legend that Manson prepares for his anesthetic lectures by sniffing halothane! They even built the incident into the Senior Class Graduation Play last year. What a roast!"

     "And how do you explain what Ledbetter did to Wong?"

     "Hey, look, buddy. This is a meritocracy. Ledbetter doesn’t put up with dumb shits."

     "And Gunnison?"

     "That guy pisses even me off."

     Our conversation meandered on, finally settling into a discussion of Ledbetter’s science. It didn’t reveal any special knowledge which would be helpful to Ledbetter as a poisoner. But somehow I didn’t feel right about checking him off the list, just yet. Damn old Burk and his flunky Jake Brown for being so slow on those neurotoxin assays!