Mike pointed at the industrial wheelie bins scattered outside; the huge weeds sprouting from the wall at various heights above the entrance. ‘Guess they’re still after that break.’

‘Ready?’ Hawkins killed the engine, cutting the tempered din still coming from the speakers. Immediately she and Maguire exchanged glances.

Because the music hadn’t stopped.

It grew louder as they both stepped out of the car and headed for the lock-up’s large red doors. Hawkins scanned the modern flats lining the far side of the street, wondering what the quieter residents thought of their neighbours’ no doubt regular practice sessions.

She turned back as they neared the entrance, passing trolleys of plastic delivery crates apparently belonging to the next arch along, pleased to find the authentically worn gate ajar.

Inside, the remnants of daylight were replaced by the pulsating glow from several banks of portable lamps stacked either side of a makeshift stage that ran the far width of the semicircular cavern. Shadows danced across the bare bricks of the archway, also illuminating rows of metal-framed bunk beds tucked into the diminishing edges of the space. A transitory kitchen filled part of the central floor area, flanked by three large sofas with upturned crates serving as coffee tables.

And on the stage, between stacks of speakers designed to entertain a room three times the size, five figures thrashed in time to their own viscous din. At the back, almost lost in the deeper shadows, a shaven head in shades bounced above a large drum kit, flanked by two male guitarists, firing rapid chords back and forth. And up front, two attractive girls in short skirts stood together, one strumming another electric guitar; the other leaning seductively on the mic stand. In fact, all five band members had microphones, into which they were collectively bawling what was presumably a chorus.

‘Let me be your generator. GENERATOR.’

Hawkins moved further in, surprised by the humidity just steps from the outside cold. Next came the smell of cigarette smoke, overlaid by the unmistakable stench of strong cannabis, and the pungent odour of five people occupying what was effectively a large bedsit.

She and Maguire stopped partway between door and stage, still fifteen feet from the band, still apparently unnoticed. Hawkins winced as the volume climbed again, but she was unable to deny that the group, despite the hostile intensity of their music, were professionals, sharp and coordinated; the overall sound cohesive, at least. She glanced at her partner, realized he was nodding along.

‘Good evening, Hammersmith. Thanks for coming out tonight.’

Hawkins turned back to the stage, where the drummer, clearly having noticed his uninvited audience of two, was now pointing at her and Mike with both arms extended over his kit. His bandmates looked up without breaking rhythm.