‘The container itself was the first signature,’ Bill told her. ‘It’s a fifteen-litre Artame pressure cooker, and that was exactly the same make and model that was used for all three of the bombs that they found up North. You can buy them online of course and we can check with the UK manufacturer to find out who might have ordered one from Ireland. The only place in Cork that stocks them is Kitchen Magic on the Grange Industrial Estate at Ballycurreen, and they should have a record of any that were bought in the past few weeks. They cost over three hundred and fifty euros each, so I doubt if they’ve sold too many of them.’

‘Expensive tastes, these terrorists,’ said Robert.

‘I think it was the casing they were going for. The best-quality shrapnel money could buy.’

‘Jesus. You have to wonder how anybody can think like that. Don’t they have brothers and sisters of their own?’

Bill Phinner clicked to the next picture on the screen, which showed a stack of purple-coloured bricks. ‘The second signature was the unusual type of charge that was used in all four bombs. It was this Semtex-1K, which was formulated for blasting work in very confined and risky surroundings, like collapsed mineshafts and half-demolished buildings. It’s very malleable and stable, but it’s also fierce high explosive. As you know, there are more than forty types of Semtex, and they’re all made by Explosia in the Czech Republic, but these four bombs are the only ones that have ever been found in Ireland to contain this particular variety.

‘The third signature was the activator, and this was a mobile phone. After he’d planted the bomb in the pharmacy lab, the bomber could set it off at any time, from any distance away, simply by ringing it. Now, look – the phone was blown to pieces, but we found the SIM card. It was locked, and it was damaged, but our IT genius here, Conall, was able to unlock it and retrieve a limited amount of information from it. Tell them what you found, Conall.’

Conall stepped forward and held up a sheet of notepaper. ‘I was able to find two incoming phone calls. My guess is that they were made to test that the phone was working properly, and that the device would go off without a hitch. They’re both from the same number in Ballincollig – and you won’t believe this, the number’s listed in the name of Brendan Moley.’

‘Well, that’s mockery for you,’ said Katie. She was well aware that Brendan Moley was a famous IRA activist who had been blown up by his own bomb in February 1988, along with another activist, Brendan Burns.