“We know her killer planned this all out ahead of time because he brought the silver necklace with him.”

Poitier asked, “Why would he do that? There was no evidence of sexual assault.”

“Revenge maybe. But I have some thoughts that might lead us a bit farther. We’ll need to talk to the medical examiner. I’d like to know about the student’s postmortem blood workup.” When the assistant commissioner remained staring at Rhyme, the criminalist said to him, “It would be helpful to know that now.”

“Yes. Of course.” McPherson lifted the receiver from his desk phone and made a call. He spoke for a moment to a clerk or assistant, it seemed, then he said into the mouthpiece, “I don’t care if he’s in an autopsy. The body will be just as dead when he returns. Fetch him.”

After a brief pause McPherson resumed his conversation. He looked at Rhyme, holding the phone away from his ear. “The results are in. The coroner has the report in front of him.”

The criminalist asked, “Blood alcohol?”

The question was posed. Then: “Point zero seven.”

Pulaski said, “Not legally drunk but close.”

Rhyme asked quickly, “What was she drinking?”

Poitier said, “We found Bacardi rum, eighty proof, and Coca-Cola in the car. Both open.”

“Diet or regular? The soft drink.”

“Regular.”

Rhyme then said to McPherson, “Ask the coroner her postmortem glucose level. And I don’t want the vascular system results. Those aren’t reliable; glycolysis continues after death. I want the vitreous concentration.” He explained, “No glycolytic enzymes there.”

McPherson stared. In fact, everyone in the room did.

Rhyme continued impatiently, “I want the glucose level from the vitreous fluid in her eye. It’s standard procedure. I’m sure they ran it.”

The man posed the question. The answer was 4.2 milligrams per deciliter.

“Low normal.” The criminalist smiled. “I knew it. She wasn’t drinking recreationally. If she’d mixed Coke and rum the level would be higher. Her killer forced her to swallow some rum straight and then just left the soft drink bottle open to make it look like she’d been mixing them.” Rhyme turned back to the assistant commissioner again. “Drug screen?”

Again the question was posed.

“Negative for everything.”

“Good,” Rhyme said enthusiastically. “We’re getting somewhere. Now we need to look into her job.”

Poitier said, “She was a part-time salesclerk in Nassau.”

“No, not that job. Her job as a prostitute, I mean.”

“What? How do you know?”

“The pictures.” He glanced at Poitier. “The pictures that you showed me on your iPad. She had multiple injection marks on her arm. Her blood was negative for narcotics or other drugs, we just learned, so why the tracks? Can’t be insulin; diabetics don’t inject intravenously there. No, it was probably—probably, mind you, not for certain—that she had regular blood tests for sexually transmitted disease.”