Andrews did, however, have an alibi for the night of Katy's death, and after a certain amount of aggrieved rhetoric he agreed to provide it. He had been at a poker night in Killiney with a few of "the lads," and when the game wound up around midnight he had decided not to drive home-"Cops aren't as understanding as they used to be," he said, with a wink at Sam-and had stayed in the host's spare room. He gave the names and phone numbers of The Lads, so Sam could confirm this.

"That's grand," Sam said at last. "We'll just need to do a voice lineup, so we can eliminate you as the source of the phone calls."

A wounded expression spread across Andrews's pudgy features. "I'm sure you realize it's hard for me to go out of my way for you, Sam," he said, "after the way I've been treated." Cassie started to giggle.

"I'm sorry you feel that way, Mr. Andrews," Sam said gravely. "Could you tell me what aspects of your treatment have been the problem, exactly?"

"You've dragged me in here for most of a business day, Sam, and treated me like a suspect," Andrews said, his voice swelling and quavering with the injustice of it all. I started to laugh as well. "Now, I know you're used to dealing with little scumbags with nothing better to do, but you have to realize what this means to a man in my position. I'm missing out on some wonderful opportunities because I'm here helping you out, I may have lost thousands today already, and now you want me to hang around doing some voice what-d'you-call-it for a man I've never even heard of?" Sam had been right: he did have a squeaky little tenor voice on him.

"Sure, we can fix that," Sam said. "We don't need to do the voice lineup now. If it suits you better to come back and do it this evening or tomorrow morning, outside business hours, I'll set it up then. How's that?"

Andrews pouted. The lawyer-he was the naturally peripheral type, I don't even remember what he looked like-raised a tentative finger and requested a moment to confer with his client. Sam turned off the camera and joined us in the observation room, loosening his tie.

"Hi," he said. "Exciting watching, yeah?"

"Riveting," I said. "It must be even more fun from inside."

"I'm telling you. A laugh a minute, this boy. God, did you see that bloody eye? It took me ages to cop on, I thought at first he'd just no attention span-"

"Your suspect's more fun than our suspect," Cassie said. "Ours doesn't even have a twitch or anything."

"Speaking of whom," I said, "don't schedule the lineup for tonight. Devlin's got a prior appointment, and afterwards, with any luck, he'll be in no mood for anything else." If we were really lucky, I knew, the case-both cases-could be over that evening, with no need for Andrews to do anything at all, but I didn't mention this. Even the thought made my throat tighten irritatingly.

"God, that's right," Sam said. "I forgot. Sorry. We're getting somewhere, though, aren't we? Two good suspects in one day."

"Damn, we're good," Cassie said. "Andrews high five!" She crossed her eyes, swiped at Sam's hand and missed. We were all very keyed up.

"If someone hits you on the back of the head you'll be stuck that way," Sam said. "That's what happened to Andrews."

"Hit him again and see if you can unstick him."

"My God, you're politically incorrect," I told her. "I'm going to report you to the National Commission for Squinty Bastards' Rights."

"He's giving me bugger-all," Sam said. "But that's grand; I didn't expect to get much out of him today. All I want is to rattle him a bit, and get him to agree to the voice lineup. Once we have an ID, I can put the pressure on."

"Hang on. Is he langered?" Cassie asked. She leaned forward, breath misting the glass, to watch Andrews as he gestured and muttered furiously in his lawyer's ear.

Sam grinned. "Well spotted. I don't think he's actually drunk-not drunk enough to get chatty, anyway, unfortunately-but there's a smell of booze off him, all right, when you get up close. If just the thought of coming in here got him shook enough that he needed a drink, he's got something to hide. Maybe it's just the phone calls, but…"

Andrews's lawyer stood up, rubbing his hands on the sides of his trousers, and waved nervously at the glass. "Round two," Sam said, trying to work his tie back into place. "See ye later, lads. Good luck."

Cassie aimed her apple core at the bin in the corner and missed. "Andrews jump shot," Sam said, and headed out, grinning.

We left him to it and went outside for a cigarette-it might be awhile before we got another chance. There is a little overhead bridge crossing one of the pathways into the formal garden, and we sat there, our backs against the railings. The castle grounds were golden and nostalgic in the slanting late-afternoon light. Tourists in shorts and backpacks wandered past, gawking up at the crenellations; one of them, for no reason that I could fathom, took a photo of us. A couple of little kids were whirling around the maze of brick trails in the garden, arms out superhero style.

Cassie's mood had shifted abruptly; the burst of ebullience had dissipated and she was shut away in a private circle of thought, arms on her knees, wayward wisps of smoke trailing from the cigarette burning forgotten between her fingers. She has these moods occasionally, and I was glad of this one. I didn't want to talk. All I could think was that we were about to hit Jonathan Devlin hard, with everything we had, and if he was ever going to crack then it would be today; and I had absolutely no idea what I would do, what would happen, if he did.

Suddenly Cassie's head went up; her gaze moved past me, over my shoulder. "Look," she said.

I turned. Jonathan Devlin was coming across the courtyard, his shoulders set forward and his hands deep in the pockets of his big brown overcoat. The high, arrogant lines of the surrounding buildings should have dwarfed him, but instead they seemed to me to align themselves around him, swooping into strange geometries with him at their crux, imbuing him with some impenetrable significance. He hadn't seen us. His head was down and the sun, low over the gardens, was in his face; to him we would have been only hazy silhouettes, suspended in a bright nimbus like the carved saints and gargoyles. Behind him his shadow fluttered long and black across the cobblestones.

He passed directly beneath us, and we watched his back as he trudged towards the door. "Well," I said. I mashed out my cigarette. "I think that's our cue."

I got up and held out a hand to pull Cassie to her feet, but she didn't move. Her eyes on mine were suddenly sober, intent, questioning.

"What?" I said.

"You shouldn't be doing this interview."

I didn't answer. I didn't move, just stood there on the bridge with my hand held out to her. After a moment she shook her head wryly and the expression that had startled me disappeared, and she caught my hand and let me pull her up.

We brought him into the interview room. When he saw the wall his eyes widened sharply, but he said nothing. "Detectives Maddox and Ryan interviewing Jonathan Michael Devlin," Cassie said, riffling through one of the boxes and coming up with an overstuffed file. "You are not obliged to say anything unless you wish to do so, but anything you do say will be taken down in writing and may be used in evidence. OK?"

"Am I under arrest?" Jonathan demanded. He hadn't moved from the door. "For what?"

"What?" I said, puzzled. "Oh, the caution…God, no. That's routine. We just want to update you on the investigation's progress, and see if you can help us move things forward another step."