The tide pools at Cabrillo Point were Dr. Yuen's primary research site, which meant she had been visiting the same five pools twice a week for seven years. She knew the pools in a way she did not know most things: their variation by season, the succession of species as conditions shifted, which pools held stable communities and which were always in flux. She had published three papers on the pools. She was working on a fourth. The observation that stopped her on a Tuesday in October was not scientifically meaningful, or she could not see how it was. She had the same feeling she sometimes got in the pools that she got in the pools, which was the feeling of being looked at. Not by any specific organism but by the system. She knew this was not how ecosystems worked. She wrote it in her field notebook anyway, in parentheses, as she had written it twice before in seven years. The fourth paper did not include this observation. It described the pools accurately, which meant it described a community of organisms responding to conditions. What it could not describe, and what she did not know how to describe, was the sense she had standing at the edge that the conditions included her, that the pools had incorporated her twice-weekly visits into whatever they were doing. She did not believe this. She kept the field notebooks and continued to make note of it when it happened.