Samson has just met Mantissa, a fellow student at the Institute of Esoteric Ideas, and been completely bowled over by her. Yet their absorbing conversation about flower power is cut short when Seymour Crayfish interrupts to remind Mantissa she has a date with him.

"Bye Samson", she said. "It's been good talking to you".

"Good-bye", he croaked, his voice choked with jealousy. As she left she brushed her hand lightly against Samson's. Then she was gone. Seymour Crayfish turned and walked after her. Samson sat there unable to move.

Her parting gesture had imprinted itself on his skin. For days afterwards he could still feel the fleeting touch of her fingertips. He almost expected an outline of her hand to show up as stigmata in red weals on his flesh, so distinctly had his nerve-ends memorised that brief moment of contact.

From then on, there was only one thought in his mind - Mantissa. He neglected his studies. Computers no longer held the same fascination for him: gone were the days when he could spend hours flushing out a recalcitrant program bug or tidying up the last detail of a screen format. Even his Astro-Pinball rating slumped miserably. From being a star pupil, he fell to the bottom of the class.

Since he was already in disciplinary trouble for taking the name of Megabrain in vain, this was bound to lead to his eventual downfall, but he did not care. He went around in a trance. It was as if the 1,001 thoughts that had crowded and jostled in his brain until the day he met Mantissa were just squatters who had been summarily evicted and now stood huddled miserably on the pavement with nowhere to go.

Occasionally, he saw her on her way to a lecture or in the student cafe surrounded by a group of admirers, usually - he noted bitterly - including Seymour Crayfish. On such occasions she was invariably polite and friendly towards him, though he tended to drown in a quicksand of tongue-tied embarrassment.

What Samson had not come to terms with was that Mantissa was kind to everyone. Not only was she very beautiful, she was very amiable too. Like all natives of Ghendor-Ghendoran she had a touch of the psycho-chameleon.

A psycho-chameleon is a small reptile found in the luxuriant tropical forests of Ghendor which feeds on the kaleidoscope plant. It protects itself from its enemies by sensing what would-be predators fear most and projecting just such an image back at them. By studying this lowly creature in its natural habitat, the Ghendorans eventually understood its behaviour well enough to build a micro-electronic device which mimicked some of its capabilities.

This device used sophisticated pattern-recognition algorithms to detect and enhance the minute electrical discharges given off by thinking and the latest holographic laser-imaging techniques to relay back the desired picture.

It enabled its user to present himself or herself as whatever most appealed to another being - or indeed to present a different favoured mask to several others at the same time. It did not so much falsify the facts as selectively highlight or play down aspects of the truth. Furthermore, it was small enough to be worn as a lapel-badge or brooch. This little charmer had, through the centuries, done much to safeguard the prosperity of Ghendor and its citizens.

One activity Samson did find time for in his zombie-like state was perusing the encyclodatabase for information about Mantissa's home planet. There he learned all this - but by then it was too late. He realised that neither he nor anyone else had seen the real Mantissa, but the knowledge fell on barren ground. The spell had already done its work.

One evening, the moment for which he had been yearning arrived. He was returning from a meeting with Dr Catharsis at which his recent lack of progress in his studies had been discussed and at which he and Zapple had been given one last chance to prove themselves. He decided to call in at the library at a time when it was unlikely to be crowded and do some further research on Ghendor-Ghendoran.

He entered to find the library quite deserted, except for Mantissa who was sitting at one of the encyclodata readers. She looked round and saw him.

"Oh, Samson, do you think you could do me a favour"?

"Certainly".

"I'm having trouble with this thing. Do you know how to work it"?

"Well, I've used it a good deal recently".

"That's good, because I'm stuck. I'm trying to look up an article on vegetative computer systems but I can't find any reference to it at all".

Samson made to lean over and reach the keyboard, but she moved her chair slightly aside and gestured for him to sit down.

"Make yourself comfortable", she said. "Draw up a chair".

He pulled up a seat next to her and started typing at the keys.

"It's organised as a hierarchical view-database", he explained, thrilled to be so near her and glad she had probed him on a topic where he felt himself competent.

"I press the button here and that takes us to the master bibliographic index. Now we can try under "Ve" for vegetative computing. By the way, do you know the author"?

"No. It was written by a woman, but I'm afraid I've forgotten her name".

With a great effort he wrenched himself back to the viewer. "Never mind. Let's try 'Ve'. We could go to the annual catalogue, but since we don't know the date it would take ages to step through it. Now, here we are. 'VDUs', 'Vector Processors', 'Vedic Mathematics' ... 'Vegetative Computation and Computer Systems' by Daisy Wheel. There you are. We've found it. I'll just put in a queue request and you'll have a microfiche copy waiting in your output pigeon-hole tomorrow morning".

Just at that moment Samson felt a gentle pressure against the side of his knee. He could hardly believe it. Yes, it was true - their legs had met under the table. Now they were both pressing: it could not be an accident.

"It's a dream", thought Samson. "It has to be a dream". His heart pounded and his breath came in fitful gulps as Mantissa's lips, now only centimetres away framed the kiss he had yearned for so desperately. Then he leant forward and bit her on the neck.

"Ow", she yelled. "What do you think you are doing"? She jumped up clutching her wound and staggered, crying, towards the door.

Poor Mantissa. She was used to being adored, but Samson was the only one who had still loved her when the low-battery warning indicator flashed on her chameleon brooch. That night in the library, though he had not noticed, she had deliberately left it switched off. A moment ago everything had seemed possible - and now this. Bitterly, she vowed never again to expose her naked self, and turned her camouflage device back on, retreating into the prison of her emotional armour-plating.

Poor Samson. He was still sitting there stunned by his own action, almost as distraught as Mantissa. She could not know, and nor did he, that it was the parasitic programmable virus which had infiltrated his defenceless blood-stream before he was even born that caused him to act as he did. Twice now, in its relentless quest for new host bodies, it had incited him to meaningless violence that had brought his world crashing round his ears.