There was no possibility of being able to utilise the device within the quadrangle, even if Tom could get access to one of the flats. It would be far too risky to attempt, as he had no idea what relationships the Branko family had with their neighbours. In any case, in his time at the flat while undercover he never saw them congregate anywhere other than the over-furnished lounge at the rear of the property, overlooking City Road.

The listening point, therefore, would have to be in line of sight of the rear of the flats.

He needed to get onto the fourth floor so he could identify an ideal location to site the laser-listener. That meant getting up close and personal with the Brankos’ flat, which could be dangerous but no more than other things he’d done before. It was behaviour, not presence, that caught the eye. If Tom acted like he belonged, no one would question why he was there.

‘Right,’ said Tom, fixing Pet with a stare. ‘I have to get out and recce now. I need you to go and have a coffee while I do it. I may need you in front of a computer, so I can find somewhere to set up, okay?’

‘Whatever you say, Detective. I could just go get a coffee, anyway.’

‘There’s a Café Nero just five minutes away by the Old Street roundabout. I’ll meet you there when I’m done,’ he said, getting out of the car. Throwing her the car keys, he said, ‘If I’m not back in an hour and you’ve not heard from me, get out of here and tell Mike.’ He turned and walked off towards City Road.

He wandered into a Tesco Metro Store on City Road and made straight for the till area, where there was a rack of business cards for local enterprises in the area. He helped himself to a large stack for a local mini-cab firm and slipped them into his jacket pocket before walking out.

Workmen were digging up the pavement on the approach to the estate, presumably working on subterranean digital cabling. The hole was protected with red and white plastic mobile barriers and the usual warning signs. A neon hi-visibility vest was draped over one of the barriers, discarded by a workman who was probably underground working on the unseen cables that kept the digital world turning.

Without hesitation or missing a beat in his step, Tom casually snatched the vest and slipped it on: perfect urban camouflage.