"The young woman in question had excellent teeth," Cooper said. "I am not, of course, a specialist in the field, but she had no fillings, crowns, extractions or other readily identifiable work."

Frank arched an inquiring eyebrow at me. I gave him my best puzzled look.

"The two bottom front teeth overlap slightly," Cooper said, "and one top molar is significantly misaligned, implying that she had no orthodontic work done as a child. I would hazard that the possibility of dental identification is practically nonexistent." Sam shook his head, frustrated, and went back to his notebook.

Frank was still eyeballing me, and it was getting on my nerves. I shoved myself off the wall, opened my mouth wide at him and pointed at my teeth. Cooper and O'Kelly gave me identical horrified looks.

"No, I don't have fillings," I told Frank. "See? Not that it matters anyway."

"Good girl," Frank said approvingly. "Keep flossing."

"That's lovely, Maddox," O'Kelly said. "Thanks for sharing. So in autumn of 2002 Alexandra Madison goes into Trinity, and in April 2005 she turns up murdered outside Glenskehy. Do we know what she was doing in between?"

Sam stirred and looked up, put down his pen. "Her PhD, mostly," he said. "Something to do with women writers and pseudonyms; I didn't understand the whole of it. She was doing grand, her supervisor says--a bit behind schedule, but what she came up with was good. Up until September she was living in a bedsit off the South Circular Road. She paid her way with student loans, grants, and by working in the English department and in Caffeine, in town. She had no known criminal activity, no debts except the loan for her college fees, no dodgy activity on her bank account, no addictions, no boyfriend or ex-boyfriend"--Cooper raised an eyebrow--"no enemies and no recent arguments."

"So no motive," Frank said musingly, to the whiteboard, "and no suspects."

"Her main associates," Sam said evenly, "were a bunch of other postgrads: Daniel March, Abigail Stone, Justin Mannering and Raphael Hyland."

"Bloody silly name," said O'Kelly. "He a poof, or a Brit?" Cooper closed his eyes briefly in distaste, like a cat.

"He's half English," Sam said; O'Kelly gave a smug little grunt. "Daniel has two speeding tickets, Justin has one, apart from that they're all clean as a whistle. They don't know Lexie was using an alias--or if they do, they've said nothing. According to them, she was estranged from her family and didn't like talking about her past. They don't even know where she was from; Abby thinks maybe Galway, Justin thinks Dublin, Daniel gave me a snotty look and told me that 'wasn't really of interest' to him. They're the same about her family. Justin thinks her parents were dead, Rafe says divorced, Abby says she was illegitimate . . .""

"Or maybe none of the above," Frank said. "We already know our girl wasn't above telling a few little white ones."

Sam nodded. "In September, Daniel inherited Whitethorn House near Glenskehy from his great-uncle, Simon March, and they all moved in. Last Wednesday night, the five of them were home, playing poker. Lexie got knocked out first and went for a walk around half past eleven--late-night walks were a regular part of her routine, the area's safe, the rain hadn't started in yet, the others didn't think twice. They finished up a little after midnight and went to bed. They all describe the card game the same way, who won how much on what hand--little differences here and there, but that's only natural. We've interviewed all of them several times, and they haven't budged an inch. Either they're innocent or they're dead organized."