‘We can’t let it happen,’ Katie told them. ‘It’s as simple as that. They’re dangerous enough when they’re fighting each other, but if we allow them to form an alliance and run the whole of the city’s drug trade together, they’ll be a total menace. They’ll have more money, more influence, and they’ll be able to put the squeeze on many more nightclubs and restaurants and other businesses.’

‘So what do you have in mind?’

‘One of Bill Phinner’s communications experts is trying to trace Muireann’s phone for me. If we can find out where O’Flynn and Riordan are meeting, then we can haul them both in for questioning. We don’t yet have all the evidence we need to make one hundred per cent sure that they’ll be convicted of conspiracy to murder and setting up an illegal drugs consortium – but we have enough to arrest them on suspicion of both charges.

‘I didn’t want to lift them so soon, but I don’t think we have much of a choice now. Once we have them here in the station, we can question them separately, and we can give each of them the impression that the other one was responsible for ratting on them.’

‘Do you think they’ll fall for that?’

‘I have no idea. But there’s no harm in planting the seed of suspicion in their minds, is there? They’ve been sworn enemies for years, and they’re not getting together because they trust each other. It’s because they don’t.’

‘Well, it’s worth giving it a shot,’ said Robert. ‘We’re so close to gathering enough evidence to take them to court, the both of them. If we can only persuade that Breaslain Hoobin to admit that O’Flynn sent him to bomb those students, and if Feargal Grífin can find the nerve to say that Riordan ordered him to shoot Billy Hagerty—’

He was interrupted by Katie’s iPhone playing Mo Ghille Mear.

‘Ma’am? It’s Conall, from the lab. I’ve been able to track that mobile. It was in Quinlan’s Bar on Watercourse Road to begin with, but now it’s been taken to Clery’s office building on the Old Mallow Road.’

‘Clery’s the electrical company? They closed down about six months ago, didn’t they?’

‘Yes. I just googled it. The building’s still empty as far as I can make out.’

‘How long has that phone been there now?’

‘Over ten minutes, without moving. There’s been no calls on it, in or out, not since I started to track it. I waited for a while before ringing you in case it was taken off somewhere else. But it’s a quarter to three now, and if O’Flynn and Riordan are meeting at three, I’d say that’s the likeliest location.’