They walked across to a four-storey office building. The top floor doubled as an observation post and comprised one large room with a three-hundred-and-sixty-degree outlook.

‘We can watch from up here.’ Cornish had calmed. She indicated a number of desks. There were several pairs of binoculars and a number of workstations. On one screen was a map showing marine traffic data. Another flicked between security cameras. A third had a feed from the main gate, one side showing CCTV of the barrier and the other detailing the trucks and their drivers as they were cleared to enter or leave. ‘I’ll get some food and drink sent up.’

‘Thanks,’ Holm said.

‘She’s in the fairway.’ Javed stood over by the screen showing marine traffic. He touched the screen and a pop-up appeared next to the symbol for the boat. ‘ETA thirty minutes, it says here.’

‘You saw the container loaded in Rotterdam?’ Cornish said.

‘Yes.’ Holm walked over to Javed. The screen was awash with little symbols and at intervals of thirty seconds or so there was a flicker and each symbol moved a fraction. ‘We’re guessing at some point during the crossing the cargo was transferred to the second container. The second container was loaded here, hence when it arrives it won’t be subject to a customs check.’

‘We could flag it for inspection anyway. Run it through the X-ray scanner.’

‘No. We need to let the container go so we can track it to its end point.’

‘And what if the terrorists escape?’

Holm saw Javed look away from the screen for a moment.

‘There are no terrorists,’ Holm said flatly and without much conviction. ‘We were barking up the wrong tree. The container is full of Nazi memorabilia. The stuff fuels the right-wing nutters and might well turn a few of them into terrorists. Which is why we need to get on top of it.’

‘Crap. We both know that’s rubbish. Stephen Holm wouldn’t be chasing artefacts from the Third Reich as if this was some twisted edition of the Antiques Roadshow.’

‘I told you, I’m out of favour. Destined to do the petty little jobs nobody else wants to do until the day I draw my pension. When we were here before I thought we’d cracked something big, but it turned out to be a minor case of nasty Nazis.’

‘Right, and I’m head of the Met.’ Cornish walked across to Holm and her hand brushed his forearm. ‘Look, I don’t know what’s going on, but I want you to promise me if you need help you’ll ask for it, OK?’

Holm gave a small nod of his head. Point conceded. Offer accepted.

Cornish whirled about and headed back down the stairs.

‘We should tell her the truth,’ Javed said. ‘We’re out on our own with no backup. She could come in handy.’