Angel

He had seen something. But he didn't know what. These days, if he didn't write something down in The Book, it was as if it had never happened. The Book was the only certainty in his life. If he didn't write down that he had seen something, something special (whilst he couldn't remember what he had seen, he had the lingering, fading impression that it had been special) if he didn't write it down, then it would not have happened. He didn't want that. So he opened The Book and, beneath an entry about breakfast, he wrote "Saw an Angel".