Pet came over. ‘Room 618, overlooking City Road. One of the least desirable apparently, but it will have to do.’

They took the elevator to the sixth floor and then Pet unlocked the heavy wooden door to reveal a small, one-bedroom apartment. It was sparsely but stylishly furnished with a cosy leather corner couch and a bright, modern kitchen. Floor-to-ceiling windows gave a fine view over City Road and across to the Brankos’ block of flats.

Tom pulled the sliding doors open and stepped out onto the balcony, feeling the late afternoon chill and hearing the roar of the rush hour traffic below him.

Pet joined him. ‘Is this okay?’

‘The angle’s too steep. I won’t be able to bounce the laser back to here without mirroring it somewhere else, which we don’t have time for. I need to be two floors down.’

‘So it’s useless then.’

‘Not exactly. We are in and past security. I just need to site the laser and receiver further down and then feed the wire up here. Let’s go and eat. I can think about it and then do some more research. I think there’s a café on the twenty-fourth floor.’

He rummaged in the holdall and took out a small leather pouch, which he tucked into his jacket pocket.

They left the apartment and took the lift to the twenty-fourth floor, where they followed the signs to Club Canaletto: a very sleek café with a large balcony which gave an incredible view across London. The lights were beginning to spark up as the city moved to evening time.

They sat inside, and both ordered open sandwiches and beer.

‘So what’s next, Detective?’

‘We eat this and then I’m going to find a vantage point to site the laser,’ he said through a mouthful of sandwich.

‘How are you going to do that?’

‘I’m going to test the theory that half of these apartments are empty because of foreign investors.’

‘How are you going to manage that?’

‘By knocking on the door, of course. How’s the sandwich?’

‘It’s a good sandwich, but you’re being deliberately obtuse.’

Tom said nothing but kept chewing and took a swig of his beer. He was going to try to do something he hadn’t done since Iraq. He needed to hear what the Brankos were talking about if the next part of his plan was to work. He was getting bored of being hunted.

It was time to go hunting.

*

They stood outside apartment number 418, Pet clutching her computer bag. Tom confidently rapped on the door and stood waiting patiently. He waited for a further minute before knocking again. There was only silence from within.