SHOT TO MY FEET.

“I need to get online.”

Ryan and Lô looked at me like I’d said I was joining Al Qaeda.

“Tell Schoon to stall.”

“Why?”

“Just keep this guy talking.”

I hurried to reception and made my request.

Unruffled, Tina led me to an empty office, typed a few keystrokes, and withdrew without query.

Moneypenny was all right.

Logging on, I went to the New England Journal of Medicine, called up an article, and speed-read. Scribbled notes. Moved through link after link until satisfied my understanding was adequate.

Next I entered a name and followed those loops.

A second name.

More loops.

I practically danced my way back to the conference room.

A woman had joined Ryan and Lô. She was tall, with short brown hair and acne-scarred cheeks. I placed her age at midthirties.

Lô made introductions. He didn’t look happy.

The newcomer was Maya Cotton, an ADA with the Honolulu prosecutor’s office.

Cotton and I shook hands.

“Anyway, sorry to spoil your day,” Cotton said.

“Sonofabitch.” Lô whacked a table leg with one foot.

“What?” I asked, not really interested, anxious to share my breakthrough.

“They kicked Pinky Atoa this morning.”

That surprised me. “He admitted to being involved in the Kealoha-Faalogo murder.”

Snorting in disgust, Lô gestured to Cotton.

“It turned out Atoa was actually only sixteen. The confession’s out. Since there’s really nothing else, he couldn’t be held.”

Down the hall, Schoon was still questioning Face Mask.

“Did I miss much?” I asked, gesturing at the screen.

“Spider’s reborn,” Ryan said. “Plans to join the Jesuits.”

“I know what happened.” I was so jazzed I showed no empathy for Lô’s frustration. “Spider. Xander. Lapasa. I just needed some medical info.”

“Lecture alert,” Ryan whispered to Lô and Cotton.

“I’ll keep it brief.” I was too pumped to take offense.

“And intelligible.”

“Yeah, yeah. No jargon.”

Deep breath.

“In two thousand two a pregnant woman named Lydia Fairchild applied for welfare in the UK. In addition to her unborn infant, she had two children by a man named Jamie Townsend. As part of the application process, Fairchild had to provide DNA evidence that Townsend was the father. Results showed that he was, but indicated that she wasn’t the mother.”

“Bummer,” Ryan said.

“No kidding. Fairchild was accused of fraud and her kids were taken into care. A judge ordered that a witness be present when she delivered, and that blood samples be taken from Fairchild and the baby. DNA indicated she was not the mother of that child either, even though it was a witnessed birth. A breakthrough came when lawyers discovered a similar case in Boston.”

“Thank the Lord for defense attorneys.” Lô, the king of sarcasm.

“In fact, it was the prosecutor.” I smiled at Cotton. “In nineteen ninety-eight a woman named Karen Keegan needed a kidney transplant. Her adult sons were tested for suitability as donors. Two of the three failed to match her DNA to the extent a biological child should. More sophisticated testing showed that Keegan was a chimera, a combination of two separate sets of cell lines with two separate sets of chromosomes.”

“How’d they figure that?” Ryan asked.

“Different DNA sequencing was found in tissues other than the ones originally taken from Keegan. Fairchild’s prosecutors suggested this possibility to her lawyers, and DNA samples were collected from members of the extended family. The DNA for Fairchild’s children matched that of her mother to the extent expected for a grandmother.”

“Showing she was the mother.” Cotton looked confused.

“Further tests showed that while DNA obtained from Fairchild’s skin and hair didn’t match her children’s, DNA obtained from a cervical smear was different and did match them.”

“Fairchild was carrying two different sets of genes.” Ryan simplified, but basically got it right.

“Yep.”

“That’s what this chimera thing is?” Lô.

“Yep.” I glanced at my notes.

“This is where she tells us all about it,” Ryan warned the other two.

“Two types of chimerism occur in humans. With microchimerism only a small portion of the body has a distinct cell line. Typically that arises because foreign cells have managed to stabilize inside a host.”

“Foreign?” Cotton asked.

“Could be cells originating from maternal-fetal exchange during pregnancy. For example, the fetus may pass on its stem and progenitor cells to the mother via the placenta. Because they’re undifferentiated, these cells may be able to survive and proliferate in the mother’s system. Maternal stem cells may be transferred to the fetus in the same way.”

No one said anything, so I continued.

“Microchimerism can also occur between twins. Actually, the most common form of human chimera is called a blood chimera. That results when fraternal twins share some portion of the same placenta. Blood is exchanged and takes up residence in the bone marrow. Each twin is genetically distinct except for their blood, which has two distinct sets of genes, maybe even two distinct blood types.”

“How common is it?” Ryan.

“It’s estimated that up to eight percent of fraternal twins are blood chimeras.” I thought a moment. “Things like blood transfusions or organ transplants can also produce microchimerism in a recipient.”

“That what happened to these ladies you’re talking about?” Lô asked.

“No. What Fairchild and Keegan had is a much rarer type, tetragametic chimerism. This occurs when two separate ova are fertilized by two separate sperm and produce two zygotes.”

Ryan raised a cautioning finger. “Embryos.”

“Yes, sorry. It occurs with fraternal or nonidentical twins. The embryos fuse very early in development, creating a single baby with two distinct cell lines. One set of DNA may appear in the kidney and another set may appear in the pancreas.”

Cotton summarized. “So these women, Fairchild and Keegan, each merged with her twin to form one baby with a hodgepodge of genes from both twins.”

“Yes.”

“Holy crap,” Lô said. “These people must look weird.”

“Many chimeras exhibit no overt signs of their condition. Or there may be minor peculiarities, differences in eye color, differential hair growth, that sort of thing. Others aren’t so lucky. Doctors at the University of Edinburgh treated a man who complained of an undescended testicle. When they examined him, they found he had an ovary and a fallopian tube.”

On-screen, Schoon was asking why Face Mask had been sent to Long Binh Jail.

Ryan cocked his chin toward the monitor. “What’s this got to do with Lowery?”

“He’s not Lowery.”

“Where’s Lowery?”

“Dead in Quebec.”

“The DNA says no.”

“Harriet Lowery was a chimera. She had one brown eye and one green eye. And Blaschko lines.”

No one asked, so I surged on.

“Blaschko lines appear as V’s or S’s or loops on the skin in specific parts of the body. They’re invisible under normal conditions, but certain diseases of the skin and mucosa manifest themselves according to these patterns.”

“Making them visible,” Ryan guessed.

“Yes.”

“They’re like, what? Stripes?” Lô asked.

“Blaschko lines are thought to represent pathways of epidermal cell migration during fetal development. The point is, chimeras often have them, and in one picture in Plato’s album, I could see them on Harriet Lowery’s chest.”

“Was she sick?”

“That I don’t know. But she had Blaschko lines. And according to Plato, Harriet also had mismatched eyes.”

“If she was a chimera, that would explain why her DNA didn’t match that of her sons.” Ryan was clicking.

“Exactly.”

“Meaning the guy in the pond was Spider after all.” Again, he indicated the screen. “Meaning this turkey isn’t.”

“Bingo.”

“So who is he?” Lô asked.

I rotated the team photo.

All three bunched close.

I tapped a boy standing in the back row. “This is Spider Lowery.”

“Agreed,” Ryan said.

I tapped a boy kneeling in the front row. “This is his cousin.”

“Sonofabitch,” Lô said.

“They could be twins,” Cotton said.

“Who is he?” Ryan asked.

“Reggie Cumbo,” I said. “Look at the man talking to Schoon.”

Three heads swiveled up.

“What color are his eyes?”

“Brown.”

“According to Plato, Spider’s eyes were green.”

Ryan worked it over in his mind. Then, “You’re thinking the cousins traded places back in sixty-eight. Spider went to Canada. Reggie went to Nam.”

I nodded. “The physical resemblance was good enough to fool anyone who didn’t really know them. They either swapped dental records, or somehow Reggie removed them from his file.”

“I’m lost,” Cotton said.

“I’ll fill you in later,” Lô said.

“Why?” Ryan asked me.

“I don’t know. Probably Spider got drafted and didn’t want to go. Reggie was always the more aggressive and assertive of the two, according to Plato. He may have wanted to join but couldn’t get in. He’d been arrested several times, hadn’t graduated high school. Unless Reggie tells us, we may never learn precisely why they did it.”

Ryan straightened. “How do you want to play this?” he asked Lô.

“Let me question him,” I said.

“No way.”

“I’m an anthropologist,” I pressed. “You’re a cop.”

“You weren’t kidding,” Lô said to Ryan. “The chick is good.”

“I told you.”

“What I mean is, Reggie may view me as less threatening than you.”

“I do have a badge,” Lô said.

“And a gun,” Ryan added.

“And I’m wearing this shirt.” Lô flipped the hem of yet another aloha delight.

“You two are hilarious,” I said. “But Cumbo has been granted limited immunity. Right now, he can walk anytime he wants. I can come at him from the JPAC angle. He claims he wants to die with a clear conscience. I can work that, talk about Plato, talk about getting Spider properly buried.”

“How sure are you on this chimera thing?” Lô asked.

“To be absolutely certain, I’ll need more of Harriet’s DNA. But right now, it’s the only theory that makes sense.”

Lô looked at Cotton.

“I lost Atoa. I’d like to hang something on this guy.”

“I don’t see a downside,” she said. “He’s been Mirandized. He’s got counsel. The army has a legitimate interest. Dr. Brennan’s their rep on this Spider thing.”

Lô hesitated.

Sighed.

“What the hell.”

I started toward the door.

“And, hey,” Lô said.

I turned, hand on the knob.

“Hit him with everything.”