ADRENALIN knits the chubby forehead into a furrow of concentration as the child edges down a grey corridor. Lips tightly pursed, temple throbbing, a short forefinger strokes the trigger as he prepares to unleash a hail of bullets at any movement in the gloom ahead.
The protruding metal muzzle swings back and forth menacingly - daring anyone lurking in the shadows. The machine-gun bursts into life and its fiery outpouring is cleaner than the shrill grinding of the chainsaw, a weapon which sprays blood thickly enough to obscure his vision.
In computer-literate Hong Kong, children sit transfixed before a flickering screen for up to six hours at a time, their ears echoing with shrieks, screams and gunfire and their minds absorbed in the task at hand - kill or be killed.
The game is called Doom and it is hailed by terminal 'Terminators' as the ultimate keyboard thrill, but decried by psychiatrists and software critics as one of the screen's most violent and dangerous role-playing games.
'It is a very dangerous concept for children: if they want to win, they have to kill their opponents,' Hong Kong Computer Club director Peter Leung Ching-boon said.
'If they take it into real life, they could hurt their classmates.' Doom is a game developed by a Texas software company and networked throughout the world. One version - an extensive 'taster' - can be downloaded from the global Internet system but game addicts must pay for the full, three-times-larger version of the game.