The train was already crossing the Susquehanna River. Wilmington and Philadelphia were only minutes beyond. Tess hunkered down with a map, trying to figure out if Devon’s apartment was near the train station, or if she would have to take a cab.

She had a photo of her, from last year’s Penn freshman face book. Again, she hadn’t questioned Dorie’s methods, had just paid up. It wasn’t the best reproduction, a printout from a scanned photo. Devon Whittaker appeared pretty, in a dull, flat way, but also looked much older than the average college freshman.

It was past eleven when Tess found Devon’s apartment building. She tried the buzzer in the foyer, but no one answered. She was in luck, there was an open square across the street, with a bench that afforded an unobstructed view of the building’s front door. It was cold for outdoor surveillance and she was downwind of a cheesesteak vendor, which made her ravenous. The long, gentle fall had lulled her into complacency; she hadn’t dressed warmly enough. She could get a cup of coffee, but that would present another problem common to surveillance: the bathroom issue. Tess was on mailing lists for catalogs offering all sorts of interesting solutions to this problem, but many of them were anatomically unsuitable for her. She subscribed to mind over matter. So far, it was working.

Mind over matter was still working for her, barely, when Devon Whittaker walked right by her less than two hours later. She even stopped in front of Tess, inhaled the steam blowing from the cheesesteak cart, then made a face as if she found it noxious. Tess caught up with her just outside the door to her apartment house.

“Devon Whittaker?” Nothing like a person’s name to get his or her attention.

“Yes?” She responded as anyone would, with the usual mix of suspicion and puzzlement. Who would have your name except a process server or the Publishers Clearinghouse Prize Patrol? Her key was out, she was ready to slide past Tess and into the apartment.

“I’m Tess Monaghan. I have a message for you from Sarah, your cousin.”

This interested her even more than her own name. “Is she okay? Has anything happened to her?”

“Could we talk inside? I’m chilled to the bone.”

Devon fumbled with the door, which had a balky lock, and walked up one flight to an apartment overlooking the park where Tess had been keeping her vigil. It was not a typical college girl’s apartment, furnished with cast-offs and the landlord’s things. Nor was it a pampered darling’s lair. The living room was clean and simple, with the kind of basic IKEA pieces one expected from young newlyweds. A dining area had been set up at the far end, and the kitchen was just beyond, separated by a counter. There were three closed doors off the hallway.

“Nice place,” Tess said. “Do you have a roommate?”

“No-I mean, yes, I do live with someone. You said you had news of Sarah. Is she okay?”

“As okay as anyone there, I guess. I don’t know what she looked like when she went in.”

Devon had bypassed the living room and seated herself at the dining room table, as if she wanted something large and substantial between her and the world. “She was on the verge of going into a coma.”

“I guess she’s better, then.”

“What did she want to tell me?”

“Actually-” how Tess hated that word, how she disliked the part of her job where she admitted to the half-truths already told, the deceptions and manipulations already employed. “She simply told me where to find you. I needed to talk to someone who was at Persephone’s a year ago, because there’s a possibility that a girl who’s now missing was there at the same time. Sarah told me you were there then.”

“She’s missing, but you don’t know where she was to begin with?”

“It’s complicated,” Tess said. She pulled the artist’s rendering of Jane Doe from her knapsack. Devon studied it intently, frowning.

“This face is a little too round,” she said at last, “and her hair was much fuller, very thick and dark. But it could be Gwen Schiller.”

Gwen Schiller. Tess tested the name, and it felt right. Gwen Schiller. She took the sketch back from Devon, looked at it. Gwen Schiller, Gwen Schiller, Gwen Schiller.

“I suppose her father hired you?” Devon asked. “About time.”

“No. Until you told me her name, I didn’t know who she was. Who’s her father?”

“Dick Schiller, of course.”

Tess needed a second, maybe two. “Dick Schiller, the guy who invented the e-mail software that Microsoft bought out? He’s practically a billionaire.”

“On paper,” Devon said, as if her family’s mere millions were in something else, like gold bullion. Or blue blood. “But if Dick Schiller didn’t hire you, who did?”

Her killer’s sister. But it wasn’t time to say that, not just yet. “You and Gwen knew each other at Persephone’s Place?”

“We overlapped there by several weeks last year, yes.” Devon had a natural wariness about her, she never seemed to relax.

“Who left first?”

“I did. I was discharged just before Labor Day, so I could start classes up here.”

“When did Gwen”-the name was still a wonderful novelty in her mouth-“leave the clinic?”

Unconsciously, Devon combed her blond hair toward her face, as if to cover it. She bore a superficial resemblance to Whitney, with her thin body and pale hair. But where everything about Whitney was sharp and bright, this girl seemed soft and dull.

“They didn’t tell you?”

“They wouldn’t tell me anything. I met Sarah…by accident.” True enough. “She sent me to you.”

Devon stood up abruptly, paced toward the kitchen and back, almost as if she were lost. “The thing is, you just have to make it to your eighteenth birthday. I kept telling Gwen that. Four months. Four months, and she’d have been able to check herself out, no matter what her dad and stepmother said.”

“How’s that?”

“When you’re eighteen, and you’ve been involuntarily committed-and almost everyone at Persephone’s is there involuntarily-you can petition the court, argue you’re healthy enough to leave, no longer a threat to yourself. The people at the clinic let you go if you even threaten to do it, as long as you can get up and walk around. They don’t like to go into court, and they have a waiting list, so the beds never go empty. Gwen was going to be eighteen on January thirty-first. But she couldn’t wait, so she bolted.”

“Ran away.”

“Yes, a few weeks after I left. Persephone’s kept it quiet, I guess. It wouldn’t do much for their reputation if it were known that the daughter of one of their richest, best-known clients had run away. Where is Gwen now, faking amnesia in some hospital, hoping her father will interrupt his round-the-world honeymoon and pay some attention to her?”

Tess walked over to the window, which overlooked the park where she had sat staring at the cheesesteak vendor and his stand. She had a name; Jane Doe would become Gwen Schiller within hours of her return to Baltimore. Her remains could be exhumed from the pauper’s grave in Crownsville, her case could be truly closed. But knowing who she was only made it more unfathomable that she could have gone unidentified for so long.

“Devon, I’m sorry to be the one to tell you this, but Gwen Schiller is dead. She was murdered in Baltimore last November sixteenth, probably not long after she ran away from Persephone’s. The man who killed her confessed to the crime, but she didn’t have any identification on her.”

“Gwen’s dead?” Devon’s reactions seemed a beat off. As thin as her face was, emotions took a long time reaching it. “You said last month, though?”

“No, November sixteenth a year ago.”

“It couldn’t be…it can’t.” Devon began pacing again, as if lost in her own apartment. “Gwen was so strong, so defiant. She was going to get well out of spite. She could take care of herself. She’s the last person I’d imagine dying.”