"Better take me through the case you're working then," he said quickly, reaching to switch the video camera back on and not meeting my eye the while.

I told him about Father Vincent Tyrrell asking me to find Patrick Hutton. There was no reaction from him to this, which I took to mean that they still hadn't identified the body. I told him about Miranda Hart and Jackie Tyrrell, about the meal at the Octagon with Seán Proby, about getting a late call from Jackie Tyrrell, about the ten-year-old controversy surrounding F. X. Tyrrell's Gold Cup-winning horse By Your Leave and the race meeting at Thurles where the horse met her death. There wasn't a single thing I said that couldn't have been discovered with an Internet connection and, possibly, five minutes' chat with a racing journalist, or failing that, with one of the standing army of punters all over the city who divided their time between pub, bookie's and social welfare office, with the exception of the late-night drink with Jackie Tyrrell. Once he had established that Jackie had called to invite me over, and I had assured him that our conversation was largely about Jackie's anxiety that Miranda not be hurt in the process of finding Patrick Hutton, he was nodding as if our business was done.

"And were Mrs. Tyrrell's anxieties really enough to get you driving into the mountains in the middle of the night?"

"Well, I hoped I'd get more from her than anxiety, hoped she had something to tell me about Hutton's disappearance, something nobody knew but her. I hoped in vain."

When I'd finished, Geraghty looked at his watch, snapped the tape player off and stood up.

"As I say, Loy, we don't think you're in the frame for Mrs. Tyrrell. I've got an important case. You're free to go. Just make sure you're available for further questioning…and watch your step, am I clear?"

"I think so," I said.

But Myles Geraghty was far from clear, and as I walked down Harcourt Street to Stephen's Green and into the thick of the last hurling wave of Christmas shoppers in the icy morning, I set to wondering why. Geraghty had hoped to flatter me into dishing the dirt on Dave, but as soon as I suggested Dave was concerned about his wife, he backed off so quickly he was practically helping my coat onto me to get me out the door. Did he have a crush on her? There couldn't be anything going on between them, that was inconceivable, Carmel 'd never have an affair, full stop. Still, Dave had not looked happy the other night, and he was a tough old bastard; maybe a few hard chaws in the Bureau were giving him a hard time, but all that "anonymous phone call, loaded gun" malarkey, it may have been happening, but I couldn't see it getting to him like that. You never really knew what went on in someone else's marriage, no matter how well you thought you knew them. And you were better off that way, as far as I was concerned.

When I got to the taxi rank on the Green, I texted Dave and asked him to call me when he could. There was a message on my phone from Tommy Owens:

Took the car before the cops arrived. Call me when you're out. T

I called him, and he told me he had ten mass in Bayview to get through, and that after that, we were taking a trip down to Tyrrellscourt. He told me why, and I told him he could drive.

But first, I needed to see a priest.

I took the Dart out to Bayview: it was as quick as a cab, and a lot cheaper, and the direction I was going, no one else was: the northbound trains were jammed with last-minute shoppers heading for the city center. The railway line hugged the coast; the bay sparkled cobalt in the bright winter light. I ran through the case in my mind. The only people who knew the man on the dump was Hutton, apart from his killer or killers, were me and Dave. But Geraghty would make the face soon enough, or someone on his team would; no more than the rest of us, Guards were desperate men for the ponies.

It was a little after ten when I got to Bayview. I bought the rest of the papers and had breakfast in a café off the main street. All the tabloids led on what they had been instructed to call the OMEGA MAN, and the broadsheets too, apart, inevitably, from the Irish Times, which preferred an EU directive on the regulation of wind farms and a Christmas Eve message of peace and goodwill from the Irish president for its leads. There was little new in any of the stories; Myles Geraghty's picture was ubiquitous in all; maybe he was employing his own publicist. When Dave's number came up on my phone, I stepped out onto the street to answer.

"Dave, what's shaking?"

Before he'd talk, I had to give him a full report on what I knew of Jackie Tyrrell's murder, and on my time with Myles Geraghty in Harcourt Square, the latter severely edited to omit any mention of Carmel, or of Geraghty's grudge against Dave.

"Makes sense Geraghty didn't waste his time with you, even for sport. The State Pathologist's reports are nearly done. Word is, Kennedy had a crucifix and an omega symbol carved into his back, at the base of his spine. And one of the boys on the scene up in Tibradden, one who's loyal to me, gave me more on Jackie Tyrrell: she was hanged, and her tongue was cut out, but she also had an amateur tattoo, the same kind as Hutton and Kennedy: a crucifix and an omega."

"So Geraghty's right, this is a serial killer."

"It looks like. Both Don Kennedy and Jackie Tyrrell had links to Patrick Hutton. Now they still haven't identified Hutton."

I thought about that. The Guards were better placed to conduct a murder investigation than I was, especially one on this scale. Keeping information from them didn't sit easily with me, particularly if that endangered people in Hutton's circle. In the end it was Dave's call.

"Strictly speaking, neither did we, Dave. We think it's Hutton, but jockeys look a lot alike. I say we keep it that way for now. We don't know what the killer wants. I'm heading down to Tyrrellscourt today. I think whatever this is about, it has its roots down there. But look, if you want to tell Geraghty who you suspect it might be…"

There was pause during which Dave digested that one. He sounded like he was chewing on a twig.

"We'll play it our way for now," Dave said gruffly. "I have enough friends at court to keep the information coming, so I'll get it to you as I hear it. You might like to let your lady friend know what's happening though. I hear they questioned all the employees up at Tibradden this morning, then let them go. They start first thing up there."

"Will do."

"And Ed, listen, about last night, in the house…you know-"

"It was very cold, wasn't it? Did you find that?"

"I made a bit of a mountain out of a molehill."

"And now you have to live on top of it. You'll need a hat. Maybe even a scarf."

"Thank you."

"Thank you."

"Leo was connected to Hutton. You don't figure him for the murders, do you? Now he's out, revenge type of thing."

"Not if one of the dead is Hutton himself. They were friends, maybe more than friends."

"But-"

"Look, Dave, I'm a private detective. I find missing persons. Solving murders, that's just not my job. What you want to do with murder, you want to get the Guards in."

MIRANDA HART WAS distraught.

"I can't believe it. Who would want to murder Jackie?"

"She said you were like a daughter to her."

"And she was like a mother to me. Oh Jesus, Ed-"

"Miranda, are you at home?"

"Yes. I'm not long here, I was up in Tibradden, but everything's canceled for the day."

"I want you to pack a bag and get out here. In fact, I'll have you collected."

"Why?"

"Because I don't think you're safe. Jackie Tyrrell is not the only one dead-"