The Republicans had put the explosive to good use. It had been the main component of the 1983 bombing of the Harrods department store in London, and the Enniskillen Remembrance Day massacre that left eleven people dead, and later it was used by the Real IRA when they killed twenty-nine men, women and children in Omagh in 1998. There wasn’t much left of the Semtex that Gaddafi had sent, but there was more than enough to blow Daniel Shepherd to kingdom come.

Liam was sitting at the kitchen table with his homework spread out in front of him and Katra was busy at the sink when Shepherd walked in. ‘Dad!’ shouted Liam, and he got up and hugged his father.

‘You should have said you were coming,’ said Katra. ‘I’d have picked you up.’

‘I didn’t want to bother you,’ he said.

‘Everything OK?’ asked Liam.

‘Sure.’

‘Where’s your bag?’ asked Katra.

‘I had to leave it behind,’ said Shepherd.

‘On the ship?’

Shepherd nodded. ‘Yeah, it was all a rush.’

‘But you’re home for a while?’

Shepherd sat down at the kitchen table and Katra went over to switch on the kettle. ‘Yes, I hope so.’

‘You work too hard,’ said Katra, taking a coffee mug from the draining board.

‘Yes, I do,’ agreed Shepherd. ‘But now I’m going to take it easy for a while.’

O’Hara brought the rental car to a halt. ‘That’s the house,’ she said. ‘See the two vehicles, the CRV and the X3?’ Eleven days had passed since O’Hara had watched Shepherd return home and it had been time well spent.

The man in the passenger seat nodded. His name was Eamonn Foley and there wasn’t a man in Ireland who knew more about blowing up cars. Foley’s forte was small controlled explosions that would kill the driver without causing much in the way of collateral damage. One of his devices had blown the legs off a High Court judge at the height of the Troubles but left his wife and two young children unharmed by the blast. It was all a matter of using the right amount of explosive and placing the device in the correct position. There were a multitude of factors to be taken into account, including the make and model of the vehicle and the weight and size of the target.

Foley had spent days studying technical diagrams of the BMW X3 and had researched everything from the thickness of the steel used in the body shell to the weight of the chassis, and he had visited several BMW showrooms to get a feel for the real thing. The bomb that he had in the holdall at his feet was a one-off, designed and built specifically for the vehicle that Shepherd drove.

The house was in darkness. The sky was overcast and the cars were far enough away from the street lights that even if someone walked by they wouldn’t be able to see anything.

‘How long, do you think?’ asked O’Hara.