‘That’s nice. Any chance of a cup of tea, love?’ Skeffington called out to the woman behind reception, who decided to ignore him.

The screen showed four images from CCTV cameras, arranged in a rectangle. Two outside, two inside the building.

‘This is from 5am two weeks ago yesterday when we open up – I’ll fast-forward till 8.30am,’ said the manager.

The first visitor, a middle-aged Asian man in a blue Ford Focus, arrived at 8.31am. He walked into reception and picked up a trolley. The cameras followed him pushing the trolley through the wide, brightly lit corridors to a row of lockers. He pulled out a piece of paper and tapped the number pad. The door swung open and he pulled out three large boxes, placed them on the trolley and then wheeled it out.

‘Not our guy,’ said Skeffington. ‘Next.’

A grey van pulled up. The timestamp was 08:39. Skeffington and Campbell sat up straight.

The door opened, and a white man in a baseball cap got out.

‘Is that him?’ asked Skeffington.

‘Think so,’ said Campbell, barely able to breathe. ‘Wait till he gets into reception – the angle is better.’

The reception camera was pointed over the shoulder of the woman on the desk – the same woman working there now by the looks of it, thought Campbell – as the man walked in. For the briefest split second, the figure looked up at the camera.

‘Yes,’ said Skeffington, so loudly that the manager started.

Campbell grabbed the sheet of paper that the manager had printed. ‘Which one is it?’ he asked.

‘There.’ The manager pointed. ‘One large locker. Three weeks’ rental. Customer reference number 56232H99. He’s calling himself Simon Gabriel.’

‘Gabriel? He’s got a nerve,’ said Skeffington. ‘Can we get in there now?’

‘Hang on a moment,’ said the manager as he typed on the keyboard. ‘You can, but the locker’s empty. He cleared it… yesterday. Came in at 10.14am and at 11.02am.’

‘Can you show us the CCTV from those times yesterday, please?’ said Campbell.

‘It’s on a different file. Hang on. It’ll take a sec to load. Got it,’ said the manager, and started the video. Again, four images – two from outside, one from the corridor and one in the reception – appeared on the screen.

‘Get ready to take his plate down,’ said Skeffington to Campbell, who scribbled the registration in his notebook. ‘Oh, bugger it. He’s walking there. There’s no van, no car, nothing.’

Abu Mujahid, this time without a baseball cap, had strolled purposefully through the car park and into the storage unit lobby. He had a rucksack on his back.

He walked past reception and appeared as a distant figure on a shot of a corridor.

‘Can’t you get the image any bigger?’ muttered Skeffington.

‘That’s as good as it gets,’ said the manager.

Skeffington swore. Abu Mujahid was too distant to see clearly, but he appeared to be removing something from the locker and putting it into his rucksack. ‘Show us the later visit,’ said Skeffington.