Prologue
Two months ago
Tucson, Arizona

Billy Nixon had been waiting his whole life to have sex with Emma Perez. Okay, not all his life. Two and a half years. It just felt that way since he’d fallen in love with her the day they met in Microeconomics, on his first day of classes at the University of Arizona. Love at first sight is a cliché, and until that moment in time Billy didn’t believe in any of that bullshit. His parents were divorced, his older sister had been in and out of bad relationships since she was fifteen, and his friends slept around as if the apocalypse was upon them.
But in the back of his mind, he remembered the story about how his grandparents met the day before his grandfather shipped off to the Korean War, how they wrote letters every week, and how three years later his grandfather came home and they married. They were married for fifty-six years before his grandfather died; his grandmother died three months later.
That’s what Billy wanted. Without having to go to war.
It took Emma two years before the same feeling clicked inside her. They’d been friends. They both dated other people (well, Billy pretended to date because he couldn’t in good conscience lead another girl on when he knew that he didn’t care about her like he cared about Emma). But it was three months ago, when Emma lost her ride home to Denver for the Christmas holidays and he found her crying in her dorm room, that he said, “I’ll drive you there,” even though he was a Tucson native and lived with his dad to save money.
From then on, she looked at him differently. Like her eyes had been opened and she saw in him what he saw in her. From that point on, they were inseparable.
The morning after they first made love, Billy knew there was no other girl, no other woman, with whom he wanted to spend the rest of his life. Call him a romantic, but Emma was it. He had started saving money for a ring. They were finishing up their third year of college, so had a year left, but that was okay. He did well in school and had a part-time job. He already had a job lined up for the summer in Phoenix that paid well, and he could live there cheaply with his sister—though the thought of spending two months with his emotional, self-absorbed sibling was a big negative. And the idea of leaving Emma for two months made him miserable. But if he did this, he’d have enough money, not only for a ring, but to get an apartment when they graduated. And—maybe—his job this summer would be a permanent thing when he was done with college next spring, which meant he’d have stability. Something he desperately wanted to provide for Emma.
Emma rolled over in bed and sighed. He loved when his dad was out of town and he had the house to himself, since they had no privacy in Emma’s dorm. Billy kissed the top of her head. He thought she was still sleeping, or in that dreamy state right before you wake up. It wasn’t even dawn, but how could he go back to sleep with Emma Perez naked in his bed?
“Billy?” she said.
“Hmm?”
“Can I ask you a favor?”
“Anything.” “I need to go to Mount Wrightson today. The Patagonia side of the mountain.”
“Okay.”
An odd request, but Emma spent a lot of time these days in the Santa Rita Mountains and surrounding areas. She was a business and environmental sciences double major who worked part-time at the Arizona Resources and Environmental Agency—AREA, as they called it—the state environmental protection agency.
“For work, school or fun?” he said.
“Last week my Geology class went out to Mount Wrightson and we hiked partway down the Arizona Trail. I noticed several dead birds off the trail. My professor didn’t think it was anything, but it bothered me. So I talked to my boss, Frank, at work, and he said if my professor didn’t think it was unusual, then it wasn’t. But I couldn’t stop thinking about it, so went back a couple days ago on my own. One of the closed trails has been used recently. And I found more dead birds, more than a dozen.”
“Which means what?”
“I don’t know yet, but birds are especially vulnerable to contaminated water because of their small size and metabolism. Remember when I told you my boss got an anonymous letter two years ago? Signed A Concerned Citizen and postmarked from Patagonia? The letter writer claimed that several local people were being made sick and that the water supply was tainted. Frank tested the water supply himself after that, but he didn’t find anything abnormal. So he dismissed it. But no one has been able to explain why those people were sick.”
“And remember—there was no evidence that anyone was sick,” Billy said. “The letter was anonymous. It could have just been a disgruntled prankster. Didn’t Frank talk to the health center about the complaint? Didn’t he investigate the local copper refinery?”
“Yes,” she said and sighed in a way that made him feel like he was missing something. “Maybe two years ago it wasn’t real,” she said in a way that made Billy think she really didn’t believe that. “But now my gut tells me something’s going on, and I want to know what.”
“You told your boss about the dead birds. You said he was a good guy, right?”
“Yeah, but I think he still thinks I’m a tree hugger.”
“You certainly gave that impression when you first started there and questioned their entire record-keeping process and the way Frank had conducted that original investigation.”
“I’ve apologized a hundred times. I realize now how much goes into keeping accurate records, and that AREA uses one of the best systems in the country. I’ve learned so much from Frank. I really believe I can make a difference now, and be smart about it too. All I want is to give him facts, Billy. And the only way I can do that is if I go back up there.”
Billy didn’t have the same passion for the environment that Emma had, but he loved her commitment to nature and how she continued to learn and adapt to new and changing technologies and ideas.
“Whatever you want to do, I’m with you,” he said. He’d follow her through the Amazon jungle if she asked him to.
“It’s going to be a beautiful day,” she said, as if he needed encouragement to do anything for her. “I just want to check out the trails near where I found the second flock of birds. We can have a picnic, make a day out of it.”
“Good call, bribing me with food.”
She smiled. “I can bribe you with something else too.” Then she kissed him.
* * *
An hour later the sun was up and they stopped for breakfast in the tiny town of Sonoita, southeast of Tucson where Highways 82 and 83 intersected. Emma had been quiet the entire drive, taking notes while analyzing a topo map.
As they ate, Emma showed him the map and her notes. “The dead birds I found last week with the class were Mexican jays. The ones I found after that on my own were trogons. I’ve been studying both of their migration patterns. The jays have a wider range. The trogons are much more localized. It seems unlikely that they just dropped dead out of the sky for no reason. I’m thinking, logically, they might have been poisoned. I don’t see any large body of water near where I found them, but there’s a pond here that forms during the rainy season.” She pointed.
While Billy couldn’t read a topo map to save his life, he trusted her thinking.
“That pond, or this stream—” she pointed again “—are right under one of their migration routes. I’ve also highlighted some other seasonal streams, here and here.”
“That seems like a huge area. North and south of Eighty-Two? How can we cover all of that in one day? Where are the roads?”
“We can hike.”
He frowned. Hike, sure. But this looked like a three-day deal.
“Emma, maybe you should talk to your boss again, show him the map and tell him what you suspect.”
“But I haven’t found anything yet—just on the map!”
Tears sprouted to her eyes, and Billy panicked. Don’t cry, don’t cry, don’t cry. “Okay, what are we doing, then?”
“If you don’t want to help me, Billy, just say so.”
“I do, Emma. I just need to know the full plan, and I don’t understand your notes. I don’t even know where exactly I’m going.”
“This is the town of Patagonia, see?” She trailed her finger along one of the paths that went from Patagonia up the mountain. “And this is Mount Wrightson, to the north.”
Billy had hiked to the peak of Mount Wrightson once. He wasn’t into nature and hiking like Emma, but he liked being outdoors, so he took a conservation class that doubled as a science requirement. His idea of being outdoors was playing baseball or volleyball or riding his bike.
“Okay.”
“We need to hike halfway up Wrightson. I found a service road that I think we can use to get most of the way to the trailhead. Okay?”
“If you’re sure about this,” he said.
She frowned and looked back down at her map. He hated that he’d made her sad.
“I’m sorry,” he said. “It’s fine.”
“You don’t want to go.”
“I do. I just don’t want us to get lost.”
She smiled sweetly at him. “Stick with me and you won’t.”
That was the smile he needed. He took her hand, interlocked their fingers. “I trust you.”
“Good.” She gave him a quick kiss, and they left the café and got back on the road.

Several hours later, Billy wasn’t as accommodating. They’d parked at the end of a dirt road near the trailhead halfway up the southeastern side of the mountain and been hiking through rough terrain ever since. The landscape was dotted with some trees and pines, but not as dense or pretty or green as on the top of the mountain. The land wasn’t dry—the wet winter and snow runoff had ensured that—so the area was hard to navigate, and the paths they were on weren’t maintained. Billy doubted they were trails at all.
The hiking had been fine up until lunch. At noon, they ate their picnic, which was a nice break, because then they had sex and relaxed in the middle of nature. It wasn’t quiet—they heard birds and a light breeze and the rustling of critters. A family of jackrabbits crossed only feet from them as they lay on the blanket Billy had brought. Afterward, Billy suggested they head back to the truck. He was tired, and they had already walked miles, which meant as many miles back to the truck.
But Emma didn’t want to leave. He was pretty sure she didn’t know exactly what she was looking for, but that she had this idea that if she walked long and far enough, she’d find evidence to support her theory that something nefarious had been happening out here to kill all those birds.
So Billy kept his mouth shut and followed her.
By four that afternoon, Billy was pretty sure Emma had gotten them lost. They had seemed to zigzag across the southern face of Mount Wrightson. He was tired, and even the birds had gone quiet, as if they were getting ready to settle in and nest for the night, even though sunset was still a few hours away.
He stopped next to a tree that was taller than most and that provided much-needed shade. It was only seventy-six degrees, but the sky was clear and the sun had been beating down on them all afternoon. He was glad he’d thought to bring sunscreen, otherwise they’d both be fried by now.
He dropped the large backpack he’d been carrying that contained their picnic stuff, blanket, water, first aid kit and emergency supplies. He knew enough about the desert not to go hiking without food and water to last at least twenty-four hours. Like if his truck didn’t start when they got back, they needed to be okay. So he had extra water—but he didn’t tell Emma that. It was for emergencies only.
“We’re down to our last water bottles,” he said. He’d paced himself so he had two left, whereas Emma had gone through all six of hers.
He handed her one of the two. “Drink.”
She sipped, handed it back to him. “Thirty more minutes, honey. See this?” She pointed to the damn map that he wanted to tear into pieces now, except without it he was positive they would be lost here forever. “That’s the large seasonal pond I was talking about. It’ll dry up before summer, according to the topo charts.”
How she could stay so cheerful when he was hot and tired and, frankly, bored, he didn’t know.
“How far?”
“Down this path, not more than two hundred yards. Three hundred, maybe.”
He looked at her. Implored her to let them start heading back.
“Why don’t you stay here and wait,” she said.
“You don’t mind?”
She smiled, walked over and kissed him. “Promise.”
Twenty minutes later she was back where Billy waited. She looked so sad and defeated. “I’m ready to go,” she said.
“We’ll come back next weekend, okay? We’ll bring a tent and food and camp overnight.”
She looked surprised at his suggestion, a smile on her face. “You mean that?”
“Absolutely.”
She threw her arms around him. “I love you, Billy Nixon.”
His heart nearly stopped. “I love you, too,” he said and held her. He wanted to freeze this moment, relive it every day of his life.
“We’re actually closer to your truck than you think—we made a circle. First we went north, then west, then south, now we’re going east again. When we get back to the main trail at the fork back there, we go left rather than right, and the truck is about half a mile up.”
He was impressed; he had underestimated her. Maybe they weren’t as lost as he thought; maybe he was the only one with a shitty sense of direction. But that was okay, because Emma loved him, and they were going to be together forever. He knew it in his heart and his head, and she’d always be there to navigate.
They drove down the mountain, the road rough at first, then it smoothed out as they got near town. They headed west on 82, deciding to drive the scenic route back to Tucson. Emma marked her map to highlight where they’d already walked, when suddenly she looked up. “Hey, can you get off here?”
“Have to pee again?”
“Ha ha. No. There’s several old roads that go south. Sonoita Creek, when it floods, cuts fast-flowing streams into the valley. We had a couple late storms this winter. I just want to check the area quickly—we’ll come back next weekend. But if I see anything that tells me the streams were running a few weeks ago, I want to come back here first. Okay? Please?”
Billy was tired, but Emma loved him, so he happily turned off the highway and followed her directions. They drove about a mile along a very rough unpaved road until they reached a narrow path. His truck couldn’t go down there—there were small cacti sprouting up all over the place, and the chances of him getting a flat increased exponentially.
Emma got out, and Billy reluctantly followed. She was excited. “See that grove of trees down there?”
He did. It looked more like overgrown brush, but it was greener than anything else around them.
“I’ll bet there’s still water. This is on the outer circle of where the birds could have flown from. I just want to check.”
“The path looks kinda steep and rocky. You sure about this?”
She kissed him. “I’m sure. Stay here, okay? I won’t be long.”
“Ten minutes.” “Fifteen.” She kissed him again, put her backpack on and headed down the path.

He sat in the back of his truck and watched Emma navigate the downward slope. He doubted this “path” had been used anytime in the last few years. From his vantage point, he saw several darker areas, plants dense and green, and suspected that Emma was right—this valley would get water after big storms.
Emma was beautiful and smart. What wasn’t to love?
He watched until she disappeared from view into the brush.
He frowned. He should have gone with her. Was he just sulking because he was tired and hungry?
Predators were out here—coyotes, bobcats, javelinas. Javelinas could be downright mean even if you did nothing to provoke them. Not to mention that these mountains bordered the corridor for trafficking illegal immigrants. Billy had taken a criminal justice class his freshman year and they touched upon that topic. He didn’t want to encounter a two-legged predator any more than one on four legs.
What kind of man was he if he couldn’t suck it up and help the woman he loved?
So he grabbed his backpack and headed down the path Emma had taken. He was in pretty good shape, but this hike had wasted him. Emma must have been fitter than he was, because she’d barely slowed down all day. After this, they’d go to his place, shower—maybe he could convince Emma to take a shower with him—and then he’d take her out to dinner. After all, they had something to celebrate: the first time they said “I love you.” They’d go to El Charro, maybe. It was Billy’s favorite Mexican food in Tucson, not too expensive, great food. Take an Uber so they could have a couple of drinks.
He wished he were there right now. His stomach growled as he stumbled and then caught himself before he fell on his ass.
He was halfway down the hill when a scream pierced the mountainside. Billy ran the rest of the way down the narrow, rocky trail. “Emma!”
No answer.
He yelled louder for her. “Emma! Emma!”
He slipped when the trail made a sudden drop as it went steeply down to a small pond—the seasonal one that Emma must have been looking for. The beauty of the spot with its trees and boulders all around was striking in the desert, and for a split second he thought it was a mirage. Then all he could think about was that Emma had been bitten by a rattlesnake, or had fallen into the water, or had slipped and broken her leg.
But she didn’t respond to his repeated calls.
“Emma!”
He stood on the edge of the pond, frantically searching for her. Looking for wild animals, a bobcat that she may have surprised. A herd of javelinas that might have attacked her. Anything.
Movement to his right startled him, and he turned around quickly.
In the shade, he saw someone. He shouted, wondering if Emma was disorientated or had gone the wrong way. But whatever he thought he saw was now gone.
Then he saw her.
Emma’s body was half in, half out of the pond, a good hundred feet beyond him, obscured in part by an outcrop of large rocks on the water’s edge. He ran to her and dropped to his knees. His first thought was that she had slipped and hit her head. Some blood glistened on her scalp.
“Emma, where are you hurt? Emma?”
She didn’t respond. Then he saw the blood on a hand-sized rock on the edge of the pond. And he felt more blood on the back of her skull.
“No, no, no!”
He saw her chest rise and fall. She was alive, but unconscious. He pulled out his phone, but there was no signal. He had to get help, but he couldn’t leave her here.
Billy picked Emma up and, as quickly as he could, carried her up the steep hillside to his truck.
As he drove back to the main road, he called 911. An ambulance met him in the closest town, Patagonia.
But by then Emma was already dead.

Excerpted from Tell No Lies by Allison Brennan, Copyright © 2021 by Allison Brennan. Published by MIRA Books.