THE snake man’s name was Stewart Butterfield, and Mona had been trying to see him since April. He was the guy Finn’s Fish and Wildlife colleagues at LAX had called in to get the snakes off the trafficker from Vietnam.
Turned out that snakes were an enthusiasm rather than a vocation for Butterfield; his day job was designing robots for the Jet Propulsion Laboratory. He explained apologetically that he’d been in Tokyo at a robotics conference, and then he had had to fly to Chile for a satellite launch, and anyway he was sorry it had taken so long to schedule a meeting. Butterfield was obviously a busy man, but Mona found that he was more than happy to talk to her about snakes—she got the impression he could talk to her for hours, so long as the subject was snakes. They were seated in comfortable armchairs in his office on the JPL campus in Pasadena. Mona had her yellow legal pad out. Butterfield wore an open-collar Oxford shirt and tortoiseshell spectacles. On the wall behind him was a framed blueprint for some kind of space vehicle.
“Is that the one that went to the moon?” asked Mona, being polite.
“Actually, that one we sent to Mars. The Sojourner rover. It’s interesting, the Sojourner ended up with traditional wheels, but one of my early designs was based on the sidewinder.”
Seeing Mona’s incomprehension, Butterfield elaborated, “You have to remember, Mars is a sandy planet, and if you want to design a robot that moves efficiently over sand, you could do worse than mimicking Crotalus cerastes, the sidewinder rattlesnake. The sidewinder undulates across the sand like a sine wave.” Butterfield waved a finger in the air to illustrate. “The sections of its body that touch the ground don’t move; only the sections lifted off the ground are in motion. That way, it never disturbs the sand. Wheels, on the other hand, move. Wheels can dig themselves in if the sand’s really soft. We didn’t know then how soft the sand was on Mars, and it doesn’t seem very clever to spend billions of dollars sending a robot to another planet just for it to get stuck.”
Mona nodded as though she followed. She was worried that if she admitted to not knowing how a sine wave moved, he’d illuminate her by making use of the whiteboard by his desk. Right at that moment, she was more interested in snakebites than sine waves.
“Sorry, I don’t mean to bore you,” said Butterfield, seeing through her polite smile. “I find snakes really interesting from a design point of view. How can I help?”
Mona told him about Carmen. He listened intently.
“I’m suing the corporation that operates the detention center for wrongful death,” she explained. “My case is based on the demonstrable fact that they built the detention center in known rattlesnake country, yet took no steps to either protect their detainees from the snakes or provide adequate treatment in the case of being bitten. I’m hoping you’ll be willing to go on the record as an expert witness on rattlesnakes.”
“Paradise is right in the heart of snake country, there’s no question. Hikers do get bitten out there, predominantly by western diamondbacks. Still, what happened to your client is extremely unusual,” he said when she had finished.
“Why?”
“Most rattlesnake bites occur late in the summer. Yet in your email, you say that your client was bitten on April 22.”
Mona sat up straight. “Do snakes hibernate?” She hadn’t even thought of it.
“Well, some species of rattlesnake brumate when the temperature drops. It’s a type of semidormancy, not unlike hibernation, except they wake up for a sip of water every now and then. But in April, they are beginning to be active anyway.”
“So they’re not fully asleep?”
“It’s not impossible that the snake that bit your client had come out of its den, for instance, to bask in the sun if it was unusually warm. It’s just extremely unlikely.”
Mona didn’t remember the day being unusually warm, but she made a mental note to check.
“And then there are some species—like the sidewinder, as a matter of fact—that aren’t dormant at all,” continued Butterfield. “They’re nocturnal in summer and diurnal in winter. But the sidewinder’s pretty shy. When people get bitten by rattlesnakes in California, most of the time it’s by a diamondback, as I said. And you hardly ever see a diamondback outside of summer.”
“Is there a way of telling what kind of snake bit her? From the venom, I mean?” asked Mona.
“Did they do a toxicological analysis?”
Mona had brought the coroner’s report with her. She handed it to him now. While he read it, her gaze drifted to a framed photo hanging by the door. It was of a rocky, rust-colored sand hill. It looked like rattlesnake country. The plaque read Mount Sharp. Mona realized, with some wonderment, that it was photo of a mountain on Mars.
“This is odd,” murmured Butterfield.
Mona turned her focus back on him. Butterfield removed his spectacles. “Like I said, most envenomations in California are by diamondbacks, and that’s what I would assume bit your client, even if it was strangely out of season. But the thing is, diamondback venom is primarily hemotoxic, rather than neurotoxic. It poisons the blood, not the nerves. If they found neurotoxin in her blood, it couldn’t be from a diamondback,” he said.
“Is there a kind of snake that would have neurotoxin in its venom?”
“Oh sure, many. The Mojave rattlesnake, for instance, has neurotoxic venom.”
“So maybe that’s what bit her?”
Butterfield put his glasses back on and read some more. After a moment, he said, “No. Definitely not a Mojave.” He leaned forward and pointed out to Mona a chart consisting of numbers and chemical symbols. Like many nonscientists, her eyes had skipped over the complex-looking chart when she’d first read the document and had gone straight to the prose summary.
“See this? It’s a chemical analysis of the toxins they found in her blood. This is the neurotoxin they found. It’s a type called dendrotoxin, and there’s only one snake in the world that produces it.” Butterfield touched the tip of the arm of his spectacles to his lower lip. He was clearly pleased with himself for connecting the dots. “The world’s most dangerous snake,” he said. “The black mamba.” He paused another moment, then added, “Endemic to central Africa.”
Mona’s heart raced. “How would someone get hold of a black mamba?” she asked.
“Legally, you mean? With great difficulty,” said Butterfield. “It’s easier to buy a semiautomatic rifle in this country than it is to buy an elapid. There’s no constitutional amendment for cobras.”
“What about illegally?”
“Well, there are ways,” said Butterfield vaguely. “Traffickers and so on. But I’m afraid I’m not involved in that world and can be of no help to you there.”
“You’ve been immensely helpful to me already, Dr. Butterfield.”
The first thing Mona did when she left Butterfield’s office in Pasadena was call Finn. She told him what she’d learned.
“If it’s from Africa, that means someone brought it into the country. I’ll call Wilkins, my buddy at Fish and Wildlife, see if he’s heard anything about a black mamba,” said Finn.
“Thanks,” said Mona. She hung up. Then she dialed Paradise Detention Center and asked to speak to the warden.
“It wasn’t a rattlesnake that bit Carmen,” she told Pischedda. “It was a black mamba, from Africa. Someone brought it into the center. I want a log of everyone who entered PDC on April 22.”
There was a long silence on the phone. Finally, Pischedda said he would be happy to release the visitor log to Mona.
“All you have to do is submit a request in writing to our legal department in Washington,” he said. “I’ll send you the log as soon as I get a green light from legal.” Pischedda hung up.
Mona reached her office when her phone started to ring again. She checked the screen. It was Finn.
“Wilkins said he hadn’t heard of anything like that, but he’d keep an eye out,” he said.
Mona thanked him. She tilted back her office chair and looked out the window at downtown. “Carmen dreamed Soto had found her,” she said.
“I know.”
“Maybe he found a way to get into PDC.”
“Yeah.”
“Nick?”
“Yeah?”
“Before she died, Carmen said she got a prison job in the canteen.”
“Okay.”
“Maws said AmeriCo sends two trucks a day out there, delivering food. To the canteen.”
A long silence.
“I’ll pick you up in twenty minutes,” he said.