“So that’s why it’s of interest to us, what with the way the lens wound up here, and how that relates to the whole history of both lighthouses,” Suzanne said from behind him. She had been having a conversation with Saul in his absence, apparently, and seemed to believe he had been responding. Behind her, Henry was about ready to collapse, although the trek had become a regular routine.

When he’d dropped the equipment and regained his breath, Henry said, “You have a marvelous view from up here.” He always said this, and Saul had stopped giving a polite response, or any response.

“How long are you here for this time?” Saul asked. This particular stint had already lasted two weeks, and he’d put off asking, fearing the answer.

Henry’s shadow-circled gaze narrowed. “This time our permit allows us access through the end of the year.” Some old injury or accident of birth meant his head was bent to the right, especially when he spoke, right ear almost touching the upward slope of his shoulder. It gave him a mechanical aspect.

“Just a reminder: You can touch the beacon, but you can’t in any way interfere with its function.” Saul had repeated this warning every day since they’d come back. Sometimes in the past they’d had strange ideas about what they could and could not do.

“Relax, Saul,” Suzanne said, and he gritted his teeth at her use of his first name. At the beginning, they’d called him Mr. Evans, which he preferred.

He took more than the usual juvenile pleasure in positioning them on the rug, beneath which lay a trapdoor and a converted watch room that had once held the supplies needed to maintain the light before the advent of automation. Keeping the room from them felt like keeping a compartment of his mind hidden from their experiments. Besides, if these two were as observant as they seemed to think they were, they would have realized what the sudden cramping of the stairs near the top meant.

When he was satisfied they had settled in and were unlikely to disturb anything, he gave them a nod and left. Halfway down, he thought he heard a breaking sound from above. It did not repeat. He hesitated, then shrugged it off, continued to the bottom of the spiral stairs.

Below, Saul busied himself with the grounds and organizing the toolshed, which had become a mess. More than one hiker wandering through had seemed surprised to find a lighthouse keeper walking the grounds around the tower as if he were a hermit crab without its shell, but in fact there was a lot of maintenance required due to the way storms and the salt air could wear down everything if he wasn’t vigilant. In the summer, it was harder, with the heat and the biting flies.

The girl, Gloria, snuck up on him while he was inspecting the boat he kept behind the shed. The shed abutted a ridge of soil and coquina parallel to the beach and a line of rocks stretching out to sea. At high tide, the sea flowed up to reinvigorate tidal pools full of sea anemones, starfish, blue crabs, snails, and sea cucumbers.