Liverpool, 17 December 1998 12.55 am

The dark blue Transit van bounced the kerb at the junction of Bold St and St Luke's Place, coming to a halt in the middle of a small pedestrianised area facing a roofless Victorian church. A three quarter moon shone down on pavements slick from recent rain and a solitary bell chimed the hour somewhere across the city. Leaving the engine running, the driver dismounted the cab and walked to the rear of the vehicle. Breath steamed from his mouth into the December night. He was tall and wore combat fatigues, black balaclava and leather gloves.

He unlocked the rear doors and pulled them open in a motion which was both efficient and unhurried. Two similarly dressed figures emerged from the darkness of the van's interior. Between them they half dragged, half lifted a stout middle aged man by the arms. His feet hit the pavement and he tumbled like a half - cut marionette. The two men roughly pulled him erect facing the rear of the van, his arms pinioned behind him. A thin trickle of blood ran from down his temple staining the starched collar of his pressed white shirt. His head rolled from side to side as he attempted to bring his eyes into drunken focus on his surroundings.

The driver gestured with his head towards a structure in the centre of the pavement area a few paces from where they stood in frozen tableau. It was a sculpture. A minimalist's idea of a Christmas tree fabricated in 16 gauge steel. Painted white, it rose thirty- five feet into the night sky. Its serrated branches tapered from base to pointed apex like the jagged teeth of an ocean predator.

In a movement which might have been rehearsed, his captors frog-marched their prisoner backwards in double time towards the tree. In a single smooth motion they hoisted and pushed the middle aged man against the tapering point of one of the lower branches. The momentum forced its tip through his torso. As it emerged on the left side of his chest, he emitted a choked moan, a mixture of surprise and agony. His chin dropped onto his collar bone and a widening patch of blood stained the pristine white of his shirt front. He was dead before he had time to register his fate.

Without looking back, the two men turned back to the van, pulling off their balaclavas as they climbed into the cab. Still efficient and unhurried, the driver closed and locked the rear doors, re-entered the cab, put the van into gear and drove smoothly off the pavement and away down the road. Within seconds the odour of exhaust fumes hanging in the dampness of the winter night was the only memento of their presence.