Ray met his gaze with a sheepish grin. "You're right. I do have an ulterior motive."

"What is it? Anything you need, man…"

"It's actually work-related, Keith. I don't know if you've heard yet, but the chairman of the Grey Rock Paiute tribe, Robert Domingo, was -"

"Yes," Keith interrupted. "I heard. It's a terrible thing. Are you working on that case? What can I do?"

"We've kept it out of the news so far, but there was a word painted on the wall near his body," Ray said. "Painted in blood, actually. 'Quantum.' Does that mean anything to you, in this context?"

Keith didn't even have to think about it. "Blood quantum? That's the formula that tribes use to determine their membership rolls."

Ray wished he had known that from the beginning. "Fascinating. Can you tell me how that works?"

"Well, every tribe can set its own standard. For the Grey Rock Paiutes, as of last fall, anyway, it's been fairly restrictive. Someone has to be able to show that they're at least half Grey Rock to be officially enrolled."

"That seems fair."

"It's a very controversial subject," Keith said. "Say someone marries outside the tribe, like Ysabel did, but for purposes of this discussion, let's say she married an Apache or a Cherokee and has kids. If Ysabel was three-quarters Grey Rock, then her kids are already out of the tribe. They might live on the reservation their whole lives, they're still native, but they're not half Grey Rock. Depending on what the other tribe's blood quantum is, they might not be Mescalero or Chiricahua or whatever, either. Then what are they? We're talking about peoples' identities, determined by the decision of a tribal membership board that might have financial motivations behind its standard."

"Financial motivations?"

Keith had clearly given the topic some thought. "Some of the poorest communities in the country are Indian reservations, Ray. But there are a few that are doing well – better than well, even. A successful casino or some energy leases can put a lot of money into a tribe's pockets. Some tribes are happy to share the wealth, but others get greedy, start cutting people out of the tribe so that the wealth doesn't have to be spread around so much."

"Is that what Grey Rock did?"

"The membership committee doesn't have to give a reason for its determination, but when they changed the standard last year, a lot of people thought that was why. The casino and spa have been making good money. With the recession, though, tourism is down, so the money they're used to pocketing has dropped some. People think they changed the blood-quantum standard as a response to the recession, so that those who make the most out of the tribal businesses can continue their standard of living, at the expense of those who are cut out."

"I can see why people would be upset about that."

"Also, some of the profits have been plowed back into the business. There's a new, higher-end casino hotel opening soon, and that's expected to be very profitable once the economy starts to come back. Most casino expansions in the city are on hold, but the tribe is cash-rich, and the project is self-financing. Whenever people start coming back to Vegas to gamble – which everybody in the city believes will happen – the Grey Rock rez will have the newest place in town. And with hotel rooms at cut rates, compared with the privately held places in the city. Which will mean yet more money divided up into fewer pieces. I don't even know that it's the money as much as the personal identity, though," Keith continued. "How finely do you want to chop yourself? Are you five-eighths Indian? Thirteen-sixteenths? Where does it end? As generations go by and there's more and more intermarrying, fewer and fewer people are left who can meet the most exacting standards. When the Grey Rock decision was made, a lot of people were ticked off. Some of them made a lot of noise, but the committee's decision is final."

"Was Domingo on the committee?"

"The way I hear it, Domingo owned the committee."

"So painting that word on the wall, in blood… the implication is that the murder was about the blood-quantum controversy. Maybe one of those angry people decided to strike back."

"That's quite possible, Ray. When you tell someone who always thought he belonged to a particular tribe that he doesn't, that tears right to the heart. Honestly, I'm a little surprised there wasn't some violence earlier on."

"You said there were complaints. Is there anyone in particular who you think might be especially angry over this? Anyone mad enough to kill?"

Keith gave a wry chuckle. "That's above my pay grade, man. I know there are some activist types who held some demonstrations, put up posters. Firebrands, you know, the kind who run every social movement. The main one, I guess, kind of a ringleader, is a filmmaker named Meoqui Torres. He's called for Chairman Domingo's resignation, demanded the blood-quantum requirements be restored to what they were before. He rubs some people the wrong way, but he has his followers, too."

"Do you think he's capable of murder?"

"I couldn't tell you that. Honestly, I barely know the guy, Ray. I'm just saying he has the loudest voice out there."

"Okay. Thanks, Keith, I appreciate it." Ray rose, extending a hand to his old friend. "If I can do anything for you – or for Ysabel – you'll let me know, right?"

Keith took Ray's hand and drew him into another hug, more awkward this time because of the living-room furniture around them. "Definitely," he said. "Listen, that reservation, with the blood-quantum debate going on and everything? It's a powder keg. Something like Domingo's murder could be the match. If you have to go out there, you watch your back, okay? Just be careful."

"I will," Ray promised.

"Good. And drop by again soon. Ysabel loves having visitors, and I know you made her day."

On his way back to the lab, Ray called Nick Stokes, who was already on the Grey Rock reservation, and told him what Keith had said. "A powder keg?" Nick asked. "Only powder I've seen is the powdered sugar on the fry bread. But I got mine with beans and salsa, so I'm cool."

"His concern sounded genuine, Nick."

"Okay, Ray. Thanks for the heads-up. Brass and I are here with the tribal police, and everything's copacetic so far. All we've learned is that Karina Ochoa definitely broke Domingo's window but probably not his head."

"Ask your tribal police escort for the two-dollar lesson on blood quantum, Nick. And maybe check on this Torres fellow. Meoqui Torres – I don't have a spelling on that first name."

"I'll check on it as soon as possible. Thanks again, Ray. I'll talk to you soon."

"Don't mention it," Ray said. But as he ended the call, he hoped Nick was taking him seriously.

Because when Keith Hyatt had talked about it, he had sounded as serious as the grave.