Alex considered this and said, “When . . . Fripp Island . . .” She hesitated. “Didn’t they say Rae was a weak swimmer? That and the riptide and the alcohol? Everyone kept saying that.”

Kim nodded. “And I remember thinking, ‘That’s not true. I’ve seen Rae swim.’ ”

“You didn’t want to say anything?”

“It didn’t seem important, I guess. Wouldn’t have made any difference to what anybody was feeling.” Kim paused. “I never mentioned any of this to a soul, not until you, now. But I think about these things sometimes . . . I wonder.”

Alex gazed at her. “You’re not sure her death was an accident.”

Kim rubbed her eye sockets with the heels of her hands.

Alex said, “Do you think someone . . . or do you think Rae . . .” Her voice shrank.

Kim sniffed, leaned back, and placed both her hands on the dock. Her eyes were bright with fresh moisture, but her voice was steady. “I have a hard time remembering much at all from that week, but when I try to think really hard about who Rae was, the feeling I have, the memory, is that she was . . . teetering. Right on the brink of something.”

“She was fourteen, so she was on the brink of something. Everything, really.”

Kim scratched at an old, scabbed-over mosquito bite on her neck. “I’ll never know what actually happened that night. But . . .” She gripped the damp wood on the underside of the dock and felt algae or mildew or some other sort of muck wedging deep and soft into her fingernails. “I think maybe some part of Rae wanted to die. Or at the very least, some part of her wasn’t so sure about the alternative. She wasn’t totally sold on it.”

It surprised Kim that she could say such a thing aloud and yet all around her the world simply carried on: the bullfrog belched, insects thrummed away, reeds shuffled and whispered against one another. No dark cloud appeared, nor any celestial ray of light. Kim felt calm and unspeakably weary. A few tears limped down her cheeks.

Eventually Alex asked, “Is that what’s been keeping you up at night?” In the months leading up to this vacation, Kim had mentioned to Alex several times that she felt tired and disorganized on account of sleeping poorly. Ever since she was a kid, really; it was nothing new, although she went through spells that were better or worse, and lately it was worse.

“Not entirely,” Kim said. “The real trouble I have with sleeping is that when I’m up in the night, I have to think every thought to its end. Not just about Rae, about everything. I have to take every single thought to its weirdest, wildest, furthest-away end. A thought won’t go away until it’s got nowhere else to go.”

Alex said, “Can you ever make it through all of your thoughts in a night? Do you ever empty yourself completely out?”