... I felt that I had successfully beaten off this intrusion of my privacy, but it had disturbed me, and I decided to pursue my research vigourously with the aim of reaching a conclusion as soon as possible. I redoubled my efforts to understand the movements of aeroplanes; how they landed, taxied, and how they appeared to burst from gravity and move through the atmosphere. It was this almost magical sight that was my chief enemy. But slowly, or quickly - I could not tell - a complicated unease overtook me; an influenza of my soul that I could not shake off. It was my landlady who disturbed me the most. Since the visit from Airport Security, she seemed to have become colder in her manner towards me. She told me angrily that she had found stains on her sitting-room furniture, stains like the trails left by slugs or snails. She looked at me as if I was in some way responsible. After some days, she appeared to have forgotten the matter, but I could not. I could not. One Sunday morning, whilst she was at church, I made a close examination of the sitting-room furniture. Evidently, every effort had been made to remove the stains, but between the seat cushion and the base of one armchair I found the remnant of a translucent, glazed deposit, crushed and smeared into the fabric. Images whirled inside my head, and I had to kneel on the carpet with my head on the floor until some wheedling familiarity had passed. Rising wearily to my feet, I made a thorough inspection of the doubleglazed louvre doors that allowed a view of the garden. I could see no possible entrance for slugs or snails, nor any further evidence of trails. I went back to my room to resume my work...