“So from that day on, what happens to the patient?” Mike asked.
“Well, that would have been a rough period for Duke Quillian, or anyone else. Trish would have been on her way home in no time, but the next four weeks, Duke would have been under strict quarantine. He would have been isolated from other patients and even visitors-we can’t have the transplant patients exposed to infection. He was put on meds to suppress his immune system, to protect against graft-host disease, to do the best to see that he’d accept the new marrow.”
Mike was checking the records of the transfusion that Anna had passed to him against the timeline of Rebecca Hassett’s murder.
“What do the dates tell you?” I asked.
“This damn record shows Duke Quillian was still a patient here six weeks later, until a full week after Bex was killed,” Mike said, his disappointment evident as he slammed the file shut. “Would he have been quarantined till then?”
Anna reached for the thick folder. “You want to get me in trouble with my administration?” she said, trying to get him to lighten up. “We can go through his chart together. It looks like Duke was clear after Day Thirty, as we call it. Day Thirty’s the critical point. That’s when the DNA tests are done. He had a cautious doctor who was trying to keep him in a safe environment before sending him out in the world.”
“What DNA tests?” I asked.
“Routine blood exams to make certain that his sister’s bone marrow had not been rejected. That the DNA being produced in Duke was actually from the cells harvested from Trish.”
“Anna,” Mike said, leaning his elbows on her desk and beaming his most earnest look in her eyes, “was he in quarantine after Day Thirty?”
She took her time, reading through the pages of fine print, vital signs, and nurses’ notes. “No. No, he wasn’t. He was moved to a room on another floor. His doctor was still doing tests. Didn’t want him discharged for another two weeks. Something about Duke’s job and the high risk of infection it posed.”
Mike was practically in her face. “So just suppose this patient was stir-crazy. Suppose he was hungry for fresh air and a walk in the park. Was he strong enough, healthy enough to do that?”
“Of course. Sure he was. He’d just have to get past hospital security.”
“Outbound? Put on his street clothes and walk out the door. You think that’s ever a problem?”
“Mike, it’s nothing our security would want to hear about.”
“I’m talking more than ten years ago, Anna. I’m not getting anyone in trouble today. On the way back in,” Mike said, pushing back to talk to me, “Duke’s already got his hospital ID and a room number. What’s to stop him from waving at the guard and going back to his room? Damn, if he didn’t ring for his bedpan during the night, who would have missed him for a couple of hours?”
“Do you have an exact date, Mike?” Anna asked.
Mike told her when Rebecca Hassett was murdered.
She studied the file again, focusing on a specific page. She scratched her forehead before looking at Mike. “I can’t say the patient didn’t have a window to-to move around. Nurses took his vital signs at the beginning and end of each shift. No other medical procedures were noted.”
Mike seemed satisfied with the doctor’s answer.
I picked up the file to look at the dates for myself. “What were you saying about DNA tests? How do they figure in this? Trish and Duke-is their DNA the same now?”
“Let me explain it, Alex. Bone marrow is what produces blood. It’s the patient’s blood that is diseased in Mr. Quillian’s kind of diagnosis, and this treatment aims to replace that blood production source entirely, with a healthy one.”
“So Trish’s bone marrow was transfused to Duke?”
“Right. On Day Thirty, Duke’s blood was checked. That’s done by DNA probes.” Anna turned the file around. “The old method at that time. RFLP, four probes.”
Restriction fragment length polymorphism, the original technique used in DNA analysis, had been replaced within the last ten years by PCR, polymerase chain reaction.
“What did that test tell them?” I asked.
“Whether the transplant had been a success. Thirty days out from the procedure, the DNA results on Duke Quillian revealed that all of his blood was produced by his sister’s bone marrow. That was great news, for him and his physicians. If he’d been relapsing, there would have been a mix of the donor’s DNA-Trish’s-with the blood still being produced by the host.”
“And for how long do they check it?”
“Six months. One year later. Maybe two or three in all. Someone young and otherwise healthy, like this Duke Quillian character was-well, we’d consider him cured after that. What his medical team would be hoping is that he’d die of old age, with his sister’s DNA, his sister’s blood,” Anna said.
“Not quite the ending he met with,” Mike said.
“So it’s like identical twins,” I said. “From the day of the transfusion on, Trish and Duke Quillian had exactly the same DNA.”
“With one twist,” Anna Borowski said. “It’s only in the blood samples of each of them that their DNA is alike.”
“What do you mean?”
“Duke’s hair, his skin cells, his saliva-even his sperm-all those tissues retain their original properties. Test any of them and they’re still unique to Duke Quillian.”
I was thinking of the skin cells from his fingers that didn’t match any of the blood extracted from the tunnel debris. Now the discrepancy was beginning to make sense.
“But his blood?” I asked.
“He had a perfect recovery from the leukemia, thanks to the bone marrow transplant from his sister.”
“And that means from that moment in time on,” I said, “that both of them-Duke and Trish Quillian-had blood with an identical DNA profile.”
42
“Just tell the lieutenant we’re in the Bronx,” I said to the detective who answered in the squad room. “We’re picking up Trish Quillian. Mike wants to go at her again, so we’ll bring her down this afternoon, if she’ll come with us.” I hung up the phone.
“I bet she has no idea what the connection was between her brother’s blood and her own DNA,” Mike said.
“You’re right. She was sixteen when they did the transplant. Not many people understood what DNA was back then. I would have thought that once the disease was cured, the patient eventually started producing his own blood again. Especially since all the rest of his DNA was intact.”
“Forget the science lesson. She’s got to know something more about Duke than she told us. And maybe it’s time for her to find out about Bex-and the pregnancy. More bones in her backyard than she ever meant to dig up. I’ve never been so happy to be spit at in my life.”
The quiet street had a series of attached houses. Once tree-lined, now there were twisted stumps and vestiges of dead trunks. Deep potholes rutted the roadway, and the cement in the sidewalks was cracked in many places.
“That’s the house,” I said, pointing ahead on the left at a small stucco building with brown shutters in sore need of a paint job.
“And there’s the detail,” Mike said, pulling over and parking in front of a gray Honda in which two detectives were sitting, in the event Brendan Quillian paid a visit.
I started to open my door to get out.
“Hold it, Coop. Slide down, keep your head out of sight if you can.”
I knew better than to ask what Mike had seen as he pulled down the visor above his head and opened the newspaper that was next to him on the front seat to screen his face.
“All clear. He’s crossing the street and getting into his car.”
When I heard the door slam and the engine start, I lifted my head. Trish Quillian was standing in the doorway, turning to take the mail from the box affixed to the side of the house.