‘Right, time to see if this works. Open Wavepad and let’s see what we’ve got. I reckon the window I have it trained on is a living room in an upstairs flat.’

Pet looked at Tom with a slightly puzzled look. ‘Is this a bug of some type?’ she asked, realisation dawning on her face.

‘Hopefully.’

The programme opened on the laptop screen and a hissing erupted from the speakers, the equaliser audio waves dancing across the screen. Pet played about with the on-screen controls, trying to filter out some of the extraneous noises. Tom saw that the laser dot on the photodiode was slightly off-centre and made a small adjustment until it was dead centre. Suddenly the hissing was replaced by the tinny tones of Jeremy Kyle haranguing some poor unfortunate individual.

A broad grin split Tom’s face. ‘Bingo. Thank goodness for the unemployed daytime TV watcher.’

‘I have to say, Detective, I’m impressed. A listening bug from a laser pointer. You are a resourceful dude. How the hell does that thing work?’

‘Simple enough: the laser bounces off the window and onto the photodiode receiver, which is translated from light waves into sound waves from the speech inside the room vibrating the window pane. It’s all about getting the trajectory right so it bounces back at the right angle.’

‘Well, I’m impressed.’

‘We just have to find somewhere to set this up near the Brankos’ address. I also think we should get out of this hotel, Pet. We’ve been here long enough.’

*

They drove along City Road in the Passat, fully aware they were in the Brankos’ stomping ground. Tom felt safe in the knowledge that he wouldn’t be expected in that area, but nevertheless kept his senses honed for any unexpected sightings.

He needed to fully scout the area around the Brankos’ maisonette so he could secure a suitable listening post in direct line of sight and on the same level. That way he could ensure that the trajectory would be appropriate to deploy the laser listening device.

He parked the car on the opposite side of the estate, on a side street off City Road. He put on the cap and spectacles in the hope it would alter his appearance as much as possible.

The premises occupied by the Brankos was in a small quadrangle. There were four storeys of dwellings, all accessible by a communal external door with lifts and stairs to each level. Each level opened onto a walkway with individual flats side by side. In the middle of all that was a neglected green space with a small swing set in the centre.

The Brankos lived in the middle of the fourth floor, overlooking the quadrangle at the front and the hustle and bustle of City Road at the rear.