The driveway opened on to a gravel strip that ran the length of the house, and the driver pulled in at the foot of a short flight of steps leading to a grand porticoed entrance. Again Bannerman told him to wait, and as he climbed the steps double doors swung open ahead of him. A soft yellow light split the darkness, throwing his shadow back down the steps and across the gravel. An elderly man wearing a neatly pressed suit and starched white collar beckoned him into a vast circular hall panelled in oak. Bannerman’s shoes resounded on mosaic tiling and he found himself facing a broad marble staircase that swept upwards in a curve to the first floor whose balcony repeated the circle before yet more stairs spiralled to the floor above. He craned his head up to see a dome of stained glass crowning the atrium. It would be magnificent in sunlight, showering shards of coloured light on to the stairs and landings. Dark, anonymous portraits stared down at him from the walls.

The man at his side coughed discreetly. ‘Your coat, sir.’ Bannerman slipped it off and Jansen’s butler draped it carefully over his arm. ‘Please follow me.’

The sound of their footsteps on the marble stairs echoed off into the vastness. The first-floor balcony was carpeted in a rich, dark blue. They walked around half of its circumference before the butler stopped to open one of the many doors leading off it. Why, Bannerman thought, when a man has all this, does he need to sell illegal arms?

He walked into a high-ceilinged room, its windows hung with velvet and looking out on to gardens at the rear of the house. An enormous marble hearth simmered in darkness. There was no fire in it, although the room was not cold. A crystal chandelier threw its almost perfect mirror reflection on to the surface of an oblong dining table of highly polished mahogany. There were places set at either end of it. A tall man in a claret smoking jacket stood waiting by one of them. The door closed behind Bannerman and the man extended his arms towards the place opposite.

‘Have a seat, Mr Bannerman. I take it you have not eaten?’