The driver made the turn onto Madison Avenue and we headed north. Vasquez put his clipboard on his lap, took Tina’s pressure, and recorded the numbers.

“You mind if I check your eyes?”

The young woman shook her head from side to side and Vasquez leaned in, studying her pupils and making a note, I guessed, about how dilated they were.

“You want to start with what happened to you, miss?”

“I’m not really sure. I know I was drugged, but that’s all I can tell you,” Tina said. “And I’ve got a terrible headache now.”

“Any idea what kind of drug?”

“Like I told Ms. Cooper, I don’t know. But I’m really thirsty,” she said, licking her lips.

“Sorry. You’re dehydrated, but the triage nurse will see you in a few minutes. No point giving you anything before that. She may want to start an IV.”

We were at the hospital in less than five minutes. It was background information about Tina Barr that I wanted-something to lead me to why she was victimized this way-but Jorge Vasquez had as much pedigree as he needed.

When he opened the rear doors of the ambulance at the hospital receiving bay, Mercer was waiting for me. I stepped around the gurney and jumped down, holding on to his hand.

“I think we’re better off keeping Ms. Barr right here till she’s called in for triage. It’s kind of zooey in there,” Mercer said.

“We can hold,” Vasquez said. “I could use the break.”

“They got a gunshot wound in the chest. Fifteen-year-old kid caught in the crossfire of two dealers. A bad car crash on the FDR Drive -three passengers with head trauma-and the typical assortment of fractures and bellyaches. You know a possible rape won’t be seen till daybreak unless you can pull some strings, Alexandra.”

Most victims of sexual assault presented to treating physicians without any external physical injury. To an emergency specialist, the trauma had occurred when the crime was committed. The survivor who presented at the hospital was not in need of life-saving treatment like the other medical patients, but rather was there for evidence collection and psychological counseling. Without advocates or forensic examiners on call, these women were often the most neglected emergency room visitors, waiting hours to be evaluated.

“We’ll try to get you in as quickly as we can,” I said to Tina, leaving her in the care of Vasquez and his partner as I turned to follow Mercer into the ER.

The security guard stood back as Mercer flashed his gold shield and the automatic double doors swung open to admit us. A dozen curtained cubicles-all seemingly occupied-formed a semicircle around the nurses’ station, where Mike had settled in with his feet on the counter, eating chocolates from a box on the desk.

“Have you spoken to the head nurse?”

“Yeah, we’re somewhere between the heart attack in that corner and the domestic dispute racheted up till the missus settled it by hurling a meat cleaver at the bum’s neck,” Mike said.

One of the nurses emerged from behind the thin curtains of the first treatment area, and Mike waved him over. “This is Ms. Cooper, Joe. You any good at splinter removal? She’s had a stick up her ass for the last couple of months, and I was hoping-”

“We’re waiting for one of the SAVI volunteers, Ms. Cooper,” Joe said, stripping his bloodied gloves off and dropping them in the hazardous-waste bin along with the syringe in his hand. He was the size of a fullback, a black man with skin as dark as Mercer’s, and not in the mood for Mike’s humor. “Get you in here as soon as we can. I’ve got one going up to X-ray and another for admission, just waiting on a room.”

“This may not have seemed urgent when the detectives first called,” I said, knowing that it might take half an hour for a sexual assault violence intervention program advocate to reach the ER, “but Tina’s in worse shape than we thought.”

I pulled the rag from my pocket, pinching it on a corner to hold it up. “The perp soaked this in something and knocked her out by putting it over her nose and mouth.”

“Nice save, Coop.” Mike stood and bent over the counter, sniffing at the rag. “What’s your guess, Joe? Ether of some kind? Not so noxious as that. Maybe chloroform?”

Joe didn’t want to come closer. “If that’s what it was, it’s enough to cause a fatal cardiac arrhythmia.”

“That baby’s going straight to the lab, Coop.”

“Tell the EMTs to bring her right in,” Joe said. “Let’s get your girl worked up.”

The three of us headed for the exit, past the waiting area filled with anxious family members and friends, down the driveway and onto the street. The driver had backed out of the bay to leave room for the next arrival and double-parked on Madison Avenue.

Jorge Vasquez was leaning against the side of the red-and-white ambulance. Mercer waved at him as we approached, telling him to move it in and unload the patient.

Vasquez shrugged his shoulders.

“Don’t give me that ‘not my job’ crap,” Mike said. “Roll it.”

“I’m empty, man,” Vasquez said, brushing his hands against each other like he was dusting off crumbs. “The broad took off.”

“Took off where?” I asked.

“RMA, Ms. Cooper. I can’t be holding nobody against her will.”

Tina Barr had refused medical attention, despite the ordeal she’d survived.

“Which way’d she go?”

“No sé,” Vasquez said. “She told me she never wanted the cops called in the first place. Jumped out the bus and said to tell you to leave her alone.”

“I still think we could have beat Tina to her apartment,” Mike said, several hours later, as he sat across the desk from me.

“To what end? For some reason, she never wanted any of us involved in the first place. It was the neighbor-not Tina-who called 911.”

“I don’t know. Should have scooped her up and made her a material witness till we figured out what happened.”

“No such thing as getting a material witness order unless there’s a pending prosecution,” I said, continuing to make notes on a legal pad, charting the chronology of a murder investigation we’d been working on for several months. “You know that.”

“Are you going to follow up with her now?”

“I’m giving Tina a day to settle down. By then she’ll realize the flashbacks and night sweats won’t go away by themselves. She might even welcome the chance to talk about it.”

We were in my office in the Sex Crimes Prosecution Unit on the eighth floor of Manhattan ’s Criminal Courthouse at nine-thirty on Wednesday morning. Mike had brought me a third cup of coffee and took the lid off after he set out his bagel on top of a file cabinet, using a manila folder as a place mat.

“How come Judge Moffett scheduled a hearing on the Griggs case? You don’t even have an arrest yet.”

We had been working on the rape-homicide of a nineteen-year-old-girl named Kayesha Avon that had taken place almost eight years earlier. The case had gone cold long ago, but the recent submission to the databank of the DNA profile of a man named Jamal Griggs and the near match that resulted had given Mike a reason to revive the investigation.

“Jamal Griggs doesn’t like the idea that we’re so interested in his family tree,” I said.

Jamal and his brother Wesley, known to us as the Weasel, had floated in and out of the criminal justice system for most of their adult lives. Despite Jamal’s homicide conviction as a teenager-or maybe because of it-he and Wesley had become part of the entourage that surrounded and sold drugs to the crews of late thug rappers such as Biggie Smalls and Tupac Shakur.

“I applied for a search warrant to get into the California database to see what it tells us about Wesley’s DNA, and must have struck a nerve. Jamal’s new counsel requested a chance to oppose my motion. I need you and Mattie Prinzer,” I said, referring to the forensic biologist who headed the lab at OCME, the Office of the Chief Medical Examiner, “to make my case.”