Mahler met her in the lobby of police headquarters. He led her upstairs to the second-floor offices and through the card-key lock. The hallway was quiet and dark. From the open door of the VCI room came the sound of a quiet conversation.

In the interview room, Mahler seated Knolls across the table and pulled a notepad and pencil toward him.

“I saw you found a dead girl at the lake,” Knolls said. “I want to make sure it’s not my Chloe.” The woman’s voice had an edge, as if used to making complaints that were unaddressed. “She ran away eight days ago. We had an argument. It wasn’t a physical thing. I didn’t hit her or anything. You probably have a record of that other time. Anyway, she walked out, and we haven’t heard from her.”

Mahler’s headache was back, a stabbing pain behind his right eye. He wished he was at home with an ice pack on his forehead.

Knolls opened her purse and pushed through the contents. “I don’t think the dead one’s my Chloe, but I couldn’t be sure. Detective Somers said the body’s taller than my daughter.”

She found what she was looking for and slid a small color photo toward Mahler. In the picture, Knolls stood beside a younger, heavier version of herself. The younger woman looked reluctantly yanked into the frame, her eyes glaring back at the camera. Mahler wondered what moment of special unhappiness was captured in the picture.

“The victim’s not your daughter.” Mahler handed back the photo.

Knolls gave no indication she’d heard Mahler. “Your kids never think bad things can happen to them.” She looked at her photo. “You can tell them, but they always know every goddamned thing.”

“Pardon my language.” She smiled crookedly, with what seemed to Mahler like artificial demureness. She put the photo away and sat with her hands resting across the top of her purse.

They were finished now, Mahler thought. He should stand and escort Knolls downstairs, but he knew she had more to say. Within his migraine, Mahler braced himself for the woman’s abrupt, cracking voice.

“Two years ago, when those other girls were killed in the park, I remember thinking, why on earth were they out there alone? Why weren’t they home?”

She seemed to consider these questions about the last mistakes of the dead. Then she said, “Chloe didn’t use to go out alone. She was a smart girl, smarter than some.”

As Mahler listened, tiny, brilliant flashes suddenly shimmered around the woman’s head. He blinked his eyes, but the flickering lights floated in space, swarming together until they coalesced into an oval bubble in front of his eyes. Inside, it was an area of total blindness.