‘You have reached your destination,’ the satnav informed them primly when they eventually turned into a wide street lined with enormous detached houses. Clara looked out at the silent buildings as their car crept slowly along, scanning each door for its number.

‘Number 82 must be up there, on the corner,’ Tom said, steering the car into a space and cutting the engine. Nobody moved.

It must have been quite a wealthy area once, Clara thought. Each of the grim, hulking Victorian buildings housing but a single family and their servants. Now, however, it had a decidedly uncared-for air, every house divided into many flats or bedsits, the paintwork peeling, the front gardens overgrown, a sense of transience and decay. Somewhere further down the street a loud party was in full swing; drunken shouts mingling with music pounding from some unseen window. Here though, all was quiet and still.

‘Well then,’ Clara said, glancing at the others uncertainly.

Number 82 was even shabbier than the rest, situated on the corner of the street, its front garden strewn with litter, six bells on the door. From somewhere further down the road a door slammed, making Clara jump, footsteps pounding on tarmac accompanied by low laughter that quickly disappeared into the silence once more. A lone car swept past. ‘Let’s check around the back first,’ Tom murmured.

Just as Zoe had said, they rounded the corner to find a small car park, empty but for a beaten-up Renault and a moped missing its front wheel. Clara nodded towards the house’s back door, a pile of over-spilling bin liners outside it. ‘That must be the door Zoe was talking about,’ she whispered. ‘Do you think it really does lead to Hannah’s flat?’ She shivered at the thought that they were so close.

They all glanced at each other. ‘Listen,’ Mac said. ‘I think I should stay out here, just in case. I can stop her if she tries to run out this way, and call the police if I need to …’

Tom nodded and looked at Rose. ‘You stay here, too,’ he said.

‘Absolutely not,’ she replied. ‘I’ve come this far. I want to see her, speak to her. I need to do this, Tom.’

For a moment he looked as though he would argue but eventually he shrugged and nodded. ‘Let’s go then,’ he said. The four of them went back to the front of the building, leaving Mac behind. As they left, Clara turned and gave him a final wave.

It was 2.40 a.m. At the front door they paused on the bottom step. Every window was in darkness, the ones on the ground floor shielded by heavy curtains. They glanced at each other nervously, then stared at the line of bells, most of them with indecipherable labels beneath peeling Sellotape, ‘Flat A’ written in smudged black ink on the first.