Of course he could only describe his impressions very lamely, for they were purely of the mind, and he had no material peg to hang them on, so that I could realise them. But the gist of it was that he had been gradually becoming conscious of what he called 'Presences' in his world. They had no effect on Space — did not leave footprints in its corridors, for instance — but they affected his mind. There was some mysterious contact established between him and them. I asked him if the affection was unpleasant and he said 'No, not exactly.' But I could see a hint of fear in his eyes.

Space (1912)