She remembered the hours they had spent studying together. His subject was Psychology. He called her the 'earth mother' because of her sunny personality and talked about displacement activity and the ideas of Freud.

Their relationship had blossomed tenderly, as first love does, then somehow they had both moved on. Another dance, a new liaison - perhaps not at first intended but growing naturally out of the opportunities created by young people thrown together. She wondered where he was now, what his children were like. Did he ever think of her.

Do we ever forget past loves or do we just learn to love others as well? she puzzled silently to herself.

Sam was standing a little apart from her near to the other window watching as she relived moments from her past. Looking across at him, for an instant, Sarah saw him as a young man, enjoying College life, loving and discovering, looking forward, full of energy and optimism. Perhaps he had been skinny then too.

His smile was kind and understanding. But it was the smile of a middle aged man who could see in her green eyes fragments of the inner journey she was on. Sensitive enough to feel the drifting images of the past from which she now was beginning to return.

"You really were gone", he said.

She nodded. Not wishing to speak yet. Her lopsided smile told him of the emotions she had felt. Instead of speaking, she linked arms with him and they walked together, side by side, to the library exit. Back in the long hall she shivered suddenly as if the shadows of the past were leaving her.

"Would you like to wander some more", asked Sam.

"Not just now, thank you. What I really want is a Gin and Tonic", she said firmly, "preferably a big one".

"There is the Union Bar", Sam said doubtfully, "but it will be a bit rowdy today and, frankly, I think, the students have seen enough of the likes of me and my colleagues for this term".

He peered at her to see her reaction.

"We could find a local pub, if you like, or alternatively we could pop round to my place round the corner. We can have a drink in my flat and then I can show you round some more."

He spoke with a smile that sought to reassure her and Sarah wondered if the suggestion was completely artless.

"I'm just a harmless old professor you know - you'll be quite safe and it'll be much more comfortable than a smoky pub", he added disarmingly. His flat was near the other end of the campus further away from Gower Street. A press button digital lock gained them entrance to the foyer.

They had passed the Computer Sciences faculty. Computers were everywhere. Large computer cabinets free standing on the floor. Smaller ones were on desks like the ones Sarah was used to. Huge disk units purred in long lines.

The lift took them to the top floor. Euston and Kings Cross were easily visible now through the large glass windows. The entrance to his flat was by security card and another password number. He happily kept up a running commentary about gigabytes and different types of LANs and CPUs.

Sarah nodded politely but was actually lost again in her own thoughts. He seemed a lonely man almost childishly pleased to have her spending some time with him. He didn't seem at all dangerous or calculating. Certainly not a leader of a criminal organisation. She must work to understand what made him tick and then perhaps she could use that knowledge of him to find what she needed to know. The first priority must be to find the computer he used for his private consultancy.

His flat was amazing. Arranged like a warehouse conversion with a huge ground floor living area, it had an open spiral staircase that climbed dizzily up to what Sarah guessed to be the sleeping area. The afternoon light cascaded through huge windows onto textured leather furniture that was dotted around in a seemingly disorganised pattern. Abstract prints were pinned haphazardly to the walls.

It was almost as if a party of people had just vacated the seats and they had been left as they landed - perhaps that was so. The kitchen she followed him into was small by comparison but led on to a dining area with another window so large that it made her feel as if she was hovering above and part of the vastness of London's Kings Cross outside.