‘DCI Hawkins,’ she offered, ‘Met Police. My colleague and I are here to see Mr White.’

Her statement had no appreciable impact on the doorkeeper, who remained motionless aside from his hollow cheeks, which flexed as if the jaw beneath his almost translucent skin was being clenched and relaxed, clenched and relaxed.

‘We have an appointment,’ she pressed.

‘I see.’ The young man spoke at last, in a poker-faced monotone, bowing his head slightly as he edged aside, allowing them to pass.

Hawkins glanced around as they entered a surprisingly small reception area given the structure’s size. Above them, a chandelier hung from the high ceiling, and ahead, a grand staircase curled upwards, disappearing out of view. Striking artwork covered every wall, but there were no seasonal decorations, despite the time of year.

The man re-secured the front door and turned to face them, his demeanour no more welcoming now they were inside. ‘Mr White will see you in his office.’

He passed them, heading for the stairs, moving with a tilted lumber that could have been the result of some congenital defect. But it didn’t slow him down, and Hawkins found herself hurrying in order to keep up as she marvelled at the images lining the walls: winged angelic figures sweeping over vivid, iridescent scenery; mythical beasts silhouetted against misted alien landscapes.

‘Are the paintings of historical significance?’ Chris asked, addressing their chaperone.

The man half turned without breaking stride, clearly having heard his visitor. But after appearing to consider the merits of answering, he simply looked away and kept climbing. Hawkins heard the junior detective tut at their guide’s insolence, but no further words were exchanged.

The upper floor presented a wide hallway with five wooden doors. The man, still unintroduced, led them towards the one at the far end, where he paused to knock.

There was a muted reply from inside, upon which Hawkins and Chris were shown through into a large office with elegant sash windows overlooking the square.

As with the rest of the building’s interior, everything structural was pure white, impeccably clean, with intricate cornicing and ceiling roses around the three lights suspended high above their heads. Plinths dotted the room’s extremities, displaying various authentic-looking relics.

A cast-iron fireplace dominated the right-hand wall, real flames dancing behind a heavy iron grille, below an elaborate gold-framed mirror. Hawkins glanced in it as she approached the desk, sardonically checking that everyone’s reflection was present and correct.

‘Good afternoon.’ A man stood up from behind the antique black desk facing the fire. He was fiftyish, with greying hair and sharp eyes. He wore a waistcoat, too, its light grey finish contrasting with his dark blue shirt.

He came forwards. ‘I’m Joseph White. You must be the detective I spoke to earlier.’

‘Yes.’ Hawkins shook his outstretched hand, introducing herself and Chris again. ‘Thanks for seeing us at short notice. Sorry I couldn’t be more specific on the phone.’