‘So she’d better not find out, right?’ Holm patted Longworth on the shoulder. ‘For both our sakes.’

Back in his office Holm made a call to Billie Cornish. The request was similar to the one he’d made to Longworth.

‘What do you want those for?’ Cornish asked. ‘You’re not keeping something from me, are you?’

Holm said he wasn’t and that he’d let her know if anything came of it.

A few hours later both requests had been granted and Holm had two sheets of paper on his desk. He skimmed through the information on both, not quite believing what he was reading.

‘OK,’ Javed said. ‘Are you going to enlighten me?’

‘Ballistic reports.’ Holm weighed the two pieces of paper. ‘One from the Met’s trip to Tunisia to investigate the cafe killings, the other from Cornish’s man-on-the-heath murder case. The bullet used to kill two of the victims in Tunisia was a nine millimetre hollow point fired from a Glock 19. Care to have a guess as to the weapon and ammunition in the Suffolk case?’

‘You’re fucking joking.’ Javed lunged for the two pieces of paper. He snatched them from Holm and peered down. ‘You’re telling me Taher killed Ben Western?’

‘To be precise I’m saying it is likely one of the guns used in the attack in Tunis was also used to kill Western, probably by Taher or an accomplice of his. Whatever, it looks like our mysterious Twitter account was on to something after all.’

The evidence was so shocking that Holm suggested they adjourn for lunch. They grabbed a couple of baguettes from a sandwich bar and walked down Millbank to find a bench. They ate by the side of the Thames.

‘People will be talking, sir,’ Javed said, gesturing at a woman who walked past. ‘That’s Julie from Cyber Security. Once she gets back inside the gossip will be spreading like wildfire. You and me sharing a quiet moment by the river.’ Javed smiled. ‘If you like, I could put my hand on your knee to stir things a little more.’

‘Fuck off.’ Holm looked pointedly at his leg. If Javed so much as brushed a hand near it he’d floor him. ‘Let’s concentrate on Western.’

‘If you say so.’

‘Boats.’ Holm nodded at the river where a tourist cruise boat was passing. No doubt the guide was pointing out the MI5 building because heads were craned to the side. ‘Ships, to be precise.’

‘SeaPak?’

‘Of course.’ Holm took a bite of his baguette. ‘SeaPak are a container shipping company. According to Cornish they bring goods in and out of the UK via Rotterdam. It seems obvious to me that Western, as a manager at SeaPak, must have been killed because he stumbled across some kind of smuggling operation. Throw Taher into the mix and what do you think was being smuggled?’

‘I don’t know, guns?’