“Each distance is a different thought process.” Susan Hart’s voice sounded mature. At twenty, she was the youngest of the park victims. But the voice in Mahler’s ear was that of a mature woman. “In the sixteen hundred, most runners slow down at the first split. I did the opposite—went for the lead after the four hundred. My father said I was like a car with an extra gear for overdrive.”

“Your coach said you had one of the strongest kicks he’d ever seen.”

“It made me fast but also got me in trouble. After I won a few races, I stopped eating because I thought it would make me lighter. That’s when I got anorexia.”

“Yeah, I know. My sister was a runner and developed anorexia. She…died.”

Susan Hart waited to see if Mahler would say more. Then she said, “A bunch of us girl runners have health issues. Lack of consecutive menstrual periods, for one. And there’s a certain body type. Small breasts.”

“I don’t feel comfortable talking about this.”

“Oh, come off it, Mister Detective. You saw my breasts. Anyway, I outgrew the issues. I’m healthy. Or, at least I was.”

“Why’re you telling me this?”

“You wanted to know who I am. I’m a runner. Running’s all about breathing, Eddie. Knowing how to breathe. Coach taught me that. It’ll be important in your new case, too—the girl you found across the lake.”

“You mean that quote on her leg?”

“You’ll figure it out.”

“Will I? I don’t see how. Nothing helps us. Look at your case. We’ve been over the evidence a hundred times.”

“It’s all there. Believe me, it’s there.”

“So what do I do?”

“Let me tell you a story.” She spoke cheerfully, as if she was enjoying herself. “I once did a training run in the dark. Down in Santa Cruz. I was on a paved road at night. In the beginning, the moonlight was enough. But after a few minutes, the moon went behind the clouds. It was so dark I couldn’t see my feet.”

“What happened?”

“Best time ever.”

“How’s that help? Tell me what you want me to do,” Mahler said. “What do you want?”

“What do you think the dead want, Eddie?”

“I don’t know. I know what the chief wants, what your father wants. But what do you want?”

Mahler waited. An animal rustled in the trees. He shivered. She was gone.

As usual, he knew the wrong things. The forensics filled a thick binder, listing the articles of clothing Susan Hart wore the day she was killed and the names of the bushes and trees that watched her die. He remembered the color of the victim’s bedroom walls, the nickname her mother had given her, and the salad that was her last meal.