"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."
CUMBO DIDN'T GLANCE UP WHEN I ENTERED THE ROOM.
Schoon and Epstein did. The lawyers watched in silence as I walked toward the table.
Up close I could see that Cumbo was sweating big-time. The collar of his hoodie was soaked with perspiration pumping from his face and neck. His eyes were underhung with flabby half-moon plums. His skin was the color of dun.
"I'm Dr. Temperance Brennan." Taking a seat.
"Doctor?" Epstein looked from me to Schoon.
"ADA Cotton suggested that I participate in this interrogation."
"Doctor?" Epstein repeated.
"I'm a forensic anthropologist."
"I don't see the relevance."
"I work for JPAC." I spoke directly to Cumbo. "The Joint POW/MIA Accounting Command. Perhaps you've heard of it?"
Cumbo didn't raise his head or acknowledge my question.
"JPAC's mission is to locate American war dead and bring them home. And they do a fine job of it."
Epstein started to object. I continued to ignore him.
"I'm involved in the case of a soldier who was killed in Vietnam, eventually buried in his home state of North Carolina."
Nothing.
"That soldier's friends and family called him Spider."
The half-moon plums pinched up ever so slightly.
"Recently an odd thing happened. A man died in Canada. Fingerprints identified that man as Spider. But Spider was buried in Lumberton, North Carolina."
Cumbo began working his thumbnails. I noticed they were yellow and ridged.
"As you can imagine, this situation created considerable confusion. The army doesn't like confusion. They opened an investigation to determine how the same man could be dead in two places."
I paused for effect.
"But I think you know."
"This is ridiculous," Epstein said.
Still I ignored him.
"Spider's real name was John Charles Lowery."
Epstein and Schoon both looked surprised. Epstein regretted it. Forced his face blank.
"But you claim you are John Charles Lowery. You say you killed Xander Lapasa in Long Binh forty years ago and assumed his identity."
Placing my forearms on the table, I leaned in.
"But John Charles Lowery never went to Vietnam. Did he, Reggie?"
Still Cumbo avoided my eyes.
"You remember Spider. You were cousins. You went to school together. Played baseball together. Wasn't it you who encouraged Spider to join the team?"
Cumbo's thumbnails were clicking double-time.
"Want to know how Spider died? He tied a rock to his ankle and drowned himself. His body's lying in a morgue in Montreal. The tag on his toe says John Doe."