Next question: What was the motive? Something was obviously going on in Eric's life that she didn't know about. She knew she had to analyze his movements in his last few days and made a mental note to check his phone records and credit card statements to see what they revealed. Three days before the murder, for example, she knew that Eric was in the Twin Cities. Why?

Next question: What was Eric doing with Tanjy Powell, and why did Tanjy disappear? Maggie didn't think it was a coincidence that, according to Stride, Eric and Tanjy met on the street on Monday afternoon, and a few hours later, Tanjy vanished. Or that two nights later, Eric was dead. She assumed that Eric was sleeping with Tanjy, even though he had spent most of December swearing on his life that he would give up his affairs. Eric was a horndog, and Tanjy was irresistible, so maybe that was the simple answer. They were having an affair that went terribly wrong, and Tanjy killed him.

Nothing else made sense.

Unless Eric sought out Tanjy because of the rape.

Maggie thought about Eric's note to her, the one he had left for her the night he died, and wondered if she had been misreading it all along. I know who it is.

Last question: Why did Eric go to see Tony the night he was killed? Tony was Maggie's own therapist, and Eric detested psychiatry on principle. So what did he want with Tony? She could drive herself crazy thinking about the possibilities, and she didn't want to wait until the morning to get an answer. Maggie slid the chair back, got up, and took the cordless phone off its cradle and punched in Tony's number from memory.

He answered on the sixth ring. "Dr. Wells."

"Tony, it's Maggie."

"Maggie," he said drowsily. "It's late."

"I know. I'm sorry."

"Are you okay?"

"I'm fine," she told him. "I need to ask you a question."

"Okay."

"Why did Eric come to see you on Wednesday night?"

Tony was silent. She felt as if she had added a new weight to his fleshy shoulders. When you spent your life with cops, sexual predators, and rape victims, you could let out the stress with sick humor or carry the heavy burden like a pack mule. Tony was a carrier, but that was what made him good.

Finally, he said, "Do you really want to do this now?"

"Yeah, I do."

"I told Abel it was a privileged conversation," Tony said. "I also told him if he thought you killed anyone, he needed a psychiatrist."

"Thanks."

"Are you sure you want the truth?"

"Why wouldn't I?"

"That depends on whether you're ready to discuss it," Tony said. "Eric told me something about you-something you obviously decided not to share with me. Although I really wish that you had come to me about this."

She closed her eyes. "That fucker."

"I'm sorry. I was going to tell you tomorrow."

"What did he want?"

Maggie tensed, waiting. Eric, what the hell did you do?

"He wanted my help in figuring out how you can spot a sexual predator," Tony went on. "He was planning to see someone after our meeting."

"Someone?"

"He didn't say who."

A few hours later, Eric was dead. Now Maggie knew why.

I know who it is.

On Sunday morning, Serena found herself among the deserted fields and open sky in the northeastern section of the city. The urban center of Duluth was clustered in a few square miles around the lake, on terraces carved into steep hills, like a miniature replica of the roller-coaster streets of San Francisco tucked into a snow globe. On the plateau above the lake, however, the land quickly leveled off and became flat and desolate. Arrow-straight highways stretched for miles. Houses were spaced far apart, with acres of land separating neighbors.

She felt as if she would drive off the end of the world if she ever reached the horizon line. Light snow skittered and danced on the asphalt like water in a sizzling pan. For Serena, there was something big and intimidating about this place. If the desert was like a snake-quick, sneaky, and secretive-then the north land was like a bear, lumbering and huge, full of fur, fat, and muscle. Living here felt like trespassing on land reserved for giants.

She turned left on a dirt road marked with a Dead End sign and drove another mile to the wooded lot where Tony Wells kept his home. It was a 1970s-era rambler, and Maggie liked to point out that the house, like Tony, was brown. Tony's SUV, a camel-colored Lexus LX, was parked in the gravel driveway.

She pulled in behind the truck and got out of her car. It was a bitter morning, the temperature hovering around zero. She exhaled a cloud of steam. Despite the cold, she always lingered here before going inside. Partly she could roll up her day-to-day worries into a ball and leave them on the hood of the car, to be picked up later. Partly she could enjoy the solitude of this peaceful, beautiful spot. The woods were made up of young birch trees and spindly brush, a tightly knit web with a carpet of snow underneath. There was hardly an evergreen anywhere, so she could see for a surprising distance through the trees. There was one narrow trail cut into the forest and cross-country ski tracks running through the snow. Another wrinkle in the trees was made by a tiny creek, now frozen solid.

She made her way around to the side of the house. Tony had built an addition onto the back for his office, with a glass wall looking out on the woods. You entered through a side door into a windowless waiting room, decorated with Ikea furniture and drab watercolors, and then you came through to this magnificent space with a vaulted ceiling and a view that stretched forever.

Tony kept a video camera overhead, so he could see patients coming into the waiting room from his desk. Serena waved at the camera and sat down. She could hear the beat of heavy metal beyond the office door.

"Walk this way," Steven Tyler sang.

Serena laughed. Like Maggie, Tony was a fanatic for hard rock, although no one would guess it by looking at him. He was the kind of serious collector who haunted eBay to find odd paraphernalia, like a hypodermic used by one of the bad boys of Mötley Crüe to shoot up with cocaine, or a maintenance memorandum about damage to a Philadelphia arena following a Metallica concert. Both were framed and hung over the sofa, next to his three University of Minnesota diplomas. He could rattle off the stats for every album, concert tour, and Grammy by Aerosmith and took two months off each summer to follow bands around the country. The flip side was that, the rest of the year, he kept office hours seven days a week. Many of his patients were cops and victims recovering from sexual trauma, so he saw people at all hours.

It was almost impossible to get a rise out of Tony, but Serena enjoyed the challenge and tried to come up with something new at every visit. Today, she got up and did a mock 1960s rock dance in front of the camera, shaking her head so that her hair twirled and pumping her arms like pistons in a go-go move. Ten seconds later, the music cut off, and the door to the office unlocked with a soft click.

She strolled inside. Tony was seated at his big oak desk in front of the glass wall. The wilderness loomed behind him. He was writing on a yellow pad and didn't look up. "Funny," he said blandly.

Serena flopped down in a sofa on the opposite side of the room. "I thought so."

Tony got up from the desk and took a seat in a leather armchair near Serena. His eyes were bloodshot. "I suppose I'm going to get another lecture now about George Strait and Diamond Rio."

"A little steel guitar wouldn't kill you, Tony."

Tony harrumphed. He was about five feet ten, with a soft, well-fed physique. He and Serena were the same age, past thirty-five and on a downward slope toward forty. He had a professorial air about him, grave and concerned, which made his taste in music seem so unlikely. But you never could tell. She knew grandmothers who collected porn. Tony wore loose-fitting tan corduroys, a white dress shirt, and a chocolate-colored vest that matched his beard and his thinning crown of hair.