The narrator suggests that Kathy might have drowned in a boating accident. She might have awoken early in the morning and turned to look at John as he slept. She would have wished that she could say something that would make him feel better, but also known that there was nothing to tell him. Perhaps she kissed John and whispered something to him.
In this hypothesis, Kathy is the victim of John’s aggression, but in a less direct way than in the earlier chapters, where he manipulates and deceives her. She seems to have given up on John, knowing that there’s no way for her to deal with his experiences in Vietnam.
After kissing John, Kathy may have showered and gotten dressed. She would have done some crossword puzzles while she ate breakfast, as was her routine—she liked to begin each day by solving things. Then, she might have gone outside and thought about how she and John never talked or made love anymore. Now that John’s political career was behind him, she may have thought, she could tell John how much she’d always hated politics, and concentrate on having a child with him. She might have secretly felt glad at that moment—glad that John was no longer a politician.
We begin to get a clearer picture of Kathy’s thoughts and feelings than we’d had in earlier chapters. Though we’ve learned a lot about what Kathy thinks of John, we know almost nothing about what she thinks about other things. Here, we learn that she’s a problem solver and an energetic, imaginative person. We also begin to sympathize with her, since she’s forced to participate in political events she doesn’t care about at all.
As she thought about John’s career, perhaps Kathy smelled the odor of dead plants and soil from the trash. As she became conscious of the smell, perhaps she remembered John’s voice and the sound of the teakettle and became conscious of what John had done the night before. Then, she would have left the house quickly and gone to the boat, perhaps forgetting her life vest.
She senses the danger and darkness within him, and because of it abandons him. Put another way: she sees through the “magic” of his façade and comes to the conclusion that she can’t help him, can’t love him, and fears him. And that fear leads to her forgetting her life vest.
Alone in the boat, Kathy may have contemplated asking John about Harmon. Perhaps while she steered the boat around nearby Magnuson’s Island, the boat hit a sandbar, injuring Kathy and throwing her into the water. Maybe this is how she died, the narrator concludes.
Again, this version of events is both satisfying and unsatisfying. It explains how Kathy died, but leaves plenty of other things unexplained, such as the identity of Harmon. O’Brien is being a little playful—we can’t accept that this is how Kathy died, because we want to know more about this mysterious new character.