‘So, what kind of a mood were the hungry wolves in?’ asked Bill. He was wearing a mustard-coloured sweater with a shawl collar and wooden buttons that made him look even more like somebody’s miserable uncle than ever. Aoife, standing close beside him, was still in her lab coat. She had bouncy brunette hair and a snub nose, which made her look more like his shy teenage niece than his new ballistics expert.

‘The press?’ said Katie, sitting down at her desk. ‘I told them that I didn’t have the first notion who might have built that bomb but I don’t think they swallowed that for a moment. Even Owen Dineen knows I’m not as thick as that, no matter what he writes about me. But of course I don’t want to give James MacGreevy even a hint yet that we suspect him. If I’d mentioned those three bombs up North, he would guess straight away that we have him in the frame.’

‘If MacGreevy owns the dog that those hairs came from, then he’s our man all right. The DNA tests have shown that it’s a billion to one that they were all shed by the same animal.’

‘Okay. We have him under surveillance but if we don’t see him with a dog within forty-eight hours I’ll ask for a search warrant. We can check then to see if we can find any more of those hairs around his house. And any bomb-making equipment at all. Even a screwdriver with a trace of that Semtex-1K on it would do it.’

‘Did the press ask you who might have had a motive for blowing up the School of Pharmacy, of all places?’

‘They did, yes, but I told them that we still had no definite leads. I’m afraid I fibbed a little. I said that we had reason to believe that the bomber could have been harbouring a personal grudge against UCC. Maybe it was a student who was kicked off his course for misconduct – stealing drugs from the lab, like, or sexual harassment.’

‘So you didn’t mention the O’Flynns or the Riordans, or some other gang?’

‘No. I want them to believe that they might have got away with it. With any luck they’ll get complacent and start boasting about it.’

Bill gave her a thumbs up. ‘That’s good thinking there, ma’am. And since we’re talking about the O’Flynns and the Riordans, we’ve come up with something that will interest you. Aoife – show DS Maguire what you have there, would you?’

Aoife came forward and set down two small plastic evidence bags on Katie’s desk. Katie picked them up and saw that each of them contained a brass cartridge case.

‘Nine-millimetre Parabellum?’ she said. She peered at them more closely. ‘They look pretty much alike to me.’