They let it pass and kept going, reaching the pavement outside the mews, where they stopped. Traffic buzzed in both directions, blinding Hawkins to distant detail, and a train thundered by above them on the wide bridge that straddled the road, its slowing clatter suggesting a nearby station. She spun, seeking a glimpse of their target.

Nothing.

‘Where the fuck did he go?’ She looked at Mike.

He pointed straight across the road, at the gate leading to the mews opposite. ‘Think he went in there?’

Hawkins turned to see another set of narrow entrances to more arches. ‘No. He won’t have cornered himself.’

She was about to suggest they take a direction each when a noise from behind, the dull shriek of metal on metal, made her turn.

For the first time, she realized the bridge that formed the corner of Albion Mews was covered in scaffolding, probably to facilitate some kind of structural repair. Her eye slid up the temporary structure to find Mardell ten feet above them, clambering frantically from bar to bar.

Heading for the railway line.

She and Mike turned to stare at each other for a second before they both ran across and grabbed the lowest poles. The steel bars were cold and wet, hard to grip; and spaced to discourage climbing. Maguire managed to swing himself up first, and extended a hand down to pull Hawkins after him.

She found a hold and wrenched herself upwards, her boot slipping off the lowest rail twice before she found anchor and was able to push on. She stared up towards the murky black clouds, to see Mardell nearing the top. She swore at the same agility that had allowed him to escape the previous night, watching him disappear over the containing wall, renewing her efforts.

Thankfully, the higher they went, the smaller the gaps between the poles became, increasing their pace. But you couldn’t guarantee survival after a fifteen-foot drop on to concrete, and cold, tiring hands became increasingly reluctant to grip the thick metal rails.

At last they hauled themselves over on to the bridge, feet hitting the loose stones that covered the surprisingly narrow gap to the first of four sets of tracks spanning the viaduct. Immediately the temperature dropped and the wind strengthened, its rushing noise filling Hawkins’ ears, dulling the sounds from the city below.

She steadied herself against the wall, staring into the darkness to their right. Thirty feet away, Mardell was trying to run on the sleepers, his stumbling progress suggesting this was no easy task, but he was heading for the lights of a station no more than a hundred yards ahead.

Mike was first to react, passing her at speed, his boots crunching against the stones. She followed, copying his tactic of sticking to the shingle. Its surface was uneven, and their pace correspondingly slow, but they seemed to be closing on Mardell, who continued to slip and falter on the slick inter-rail beams.