Without mental aid, indeed, with a headache owing to his removal of his enhancements, Cawl undertook work so complex no higher adept would dream of entrusting him with it. At risk was the precise recollection machines afforded a man. One slip could obliterate years of hard-won skill.

Sometimes he thought it would be better to have two brains rather than keep doing this.

The hole in his head was cold. The aseptic gels that filled it and kept it free of disease chilled his brain with evaporation. He did not dare cover his head over. His hood might dislodge the sterile plastek patch closing the opening. Really, really this kind of operation should only be undertaken in one of the genetors' surgical theatres.

Cawl enjoyed a challenge.

He smiled at his own audacity. Only slightly; the smallest of movements could disturb his delicate work.

Before mid-watch bell, Cawl had performed fourteen illegal procedures on his own mind. When mid-watch plus one bell sounded, signifying the start of his shift, he was rebuilding the augment.

He glanced at his chronograph as the last panel clicked into place and his mechanical tendrils whipped back into the holes in his wrists.

Cawl lifted his hands and shook them out before gingerly picking up his intelligence core. It was important they be steady. It always surprised Cawl how heavy the intelligence core was. He thrust the hand holding the core up to the wrist into a pot of biocide he kept on his desk, leaving it in the cold liquid long enough to kill every living thing on it, but removing it before his skin started to dissolve.

Next, he leaned forwards so that the mirrors he had arranged over his desk reflected the socket in his skull clearly. Ever so carefully, he peeled away the plastek patch with his left hand.

He pushed the intelligence core home with a quick, robust movement. It was important it be done firmly. An electric jag fizzed through his mind. The click as it slid into place echoed in the bone behind his nose.

'Now,' he said. 'The moment of truth.'

With the edge of a fingernail, he depressed the reset switch concealed beneath the black-and-white machina opus adorning the top of the core. Either he would be rewarded with a greater capacity for knowledge, or his brain would be cooked from the inside out.

Red diode lumens lit up around the rim of the core. When they had formed a circle, they blinked and turned green.

Cawl relaxed; he had tensed without realising it. He smiled brightly as the machine interfaced again with his brain, imposing useful readouts over his vision. Storage capacity read at twenty-five per cent full.

'Threefold increase, Tez-Lar!' he said happily. Then frowned.

He had not time to tidy away his tools. He had to trust no curious adept would glance into his room as he left it.

Cawl hurried out of his quarters, Tez-Lar stamping behind him.