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.

The beetle had been identified in 1988, described in a paper, and assigned a binomial name that included the discoverer's surname: Melanotus harrisoni. Dr. Harrison, who was twenty-nine at the time of discovery, had spent the following thirty-four years in the company of beetles without finding a second species. He had found many specimens and several subspecies and one probable hybrid, but no new species. This was not unusual. This was, in fact, the normal career arc. He knew this and continued anyway. What he had not expected was the specific quality of his relationship to Melanotus harrisoni. He collected specimens and mounted and studied them with the professional detachment appropriate to a taxonomist. He did not feel sentimental about them. But when students asked why he had stayed in a field with so few dramatic discoveries, he found himself talking about the beetle in a way that he recognized, afterward, as something closer to gratitude than he had intended. He gave a lecture each spring on the process of species identification and always began with the morning he had found the first specimen under a rotting log in West Virginia. He had not known what he was looking at, he told the students. He had put it in a vial and brought it to the lab and spent three weeks in the literature before concluding it was new. The certainty, when it came, was the most precise feeling he had ever had. He spent thirty-four more years in the field hoping to have it again.