Chapter 15 Summary and Analysis

⚠️ Spoiler Warning: This guide contains detailed spoilers for the entire novel. Proceed only if you've finished reading or are comfortable knowing the plot.

You can return to the book hub anytime, or go to the previous chapter if you need a refresher.

Otherwise, read on for a full breakdown of this pivotal chapter.

(Note: The chapter numbering in the book is confusing—this is the 23rd chapter in the overall book, but it's labeled “Chapter 15” internally.

We'll refer to it as Chapter 23 for clarity.)

Summary

The chapter opens with the group—the narrator, Riki, April, Tom, and Liani—confronting the reality that Dr. Henson is not just hard to find but genuinely missing.

The narrator and Riki had already searched the house once, but now the situation feels different.

Liani, who had earlier feared Dr. Henson might be at the bottom of the lagoon, is calmer knowing she isn't there, but the fact that she's not on the surface or anywhere else is deeply troubling.

Her texts go unread, and calls go straight to voicemail.

Tom suggests she might have taken the paddleboard to town, but Liani points out that Dr. Henson doesn't like open water, and the board is gone.

The group decides to split up: the narrator and Riki will do a second, more thorough search of the house; April and Van will continue giving tours to avoid raising suspicion; and Liani will take the Jet Ski to search the waters around the island.

They agree to meet back in an hour, and if they haven't found her, they'll call the police.

The narrator and Riki start in the basement, checking every bathroom, storage room, and mechanical space.

April joins them, and they move to the boathouse.

The boathouse is a large shed with three slips, and the Jet Ski is still gone, meaning Liani hasn't returned yet.

April insists on checking under the dock, despite Riki's warning that it's dark and full of debris.

April strips down to her underwear and jumps in, diving beneath the dock.

She doesn't find Dr. Henson, but she gets her foot caught in netting and panics.

Riki jumps in to rescue her, pulling her to the ladder.

April emerges with a long scrape down her thigh and arm, and she's shaken.

She also realizes she lost her necklace—a gift from her grandmother—in the water, but Riki stops her from diving again.

Just then, Liani returns on the Jet Ski, having found nothing.

With no other options, they call the police.

Two officers arrive by boat about fifteen minutes later.

They question the group, and the last confirmed sighting of Dr. Henson was around 8 PM the previous night, when she came down to the water to tell them about the grad student arriving the next day.

The narrator mentions seeing Dr. Henson's yoga mat mark on the balcony that morning, but no one actually saw her after the night before.

The officers take note of the missing paddleboard—purple with a wave pattern—and one officer asks to be taken to Dr. Henson's room.

The narrator guides her there.

The officer searches more thoroughly than the narrator had, opening drawers and checking the closet.

She finds Dr. Henson's keys in the bedside drawer, which is significant because it means she didn't take them with her.

The officer also asks if the narrator found any notes or messages, implying the possibility of suicide or a planned departure.

Within half an hour, a search boat with two divers arrives, and a glass-bottom-boat operator circles the island.

The group feeds the officers and helpers, and they mill around as the police search the house again, finding nothing.

Then there's a burst of activity.

A boater has reported finding a purple paddleboard with a wave pattern floating near Mulligan Island.

The officer shows the group a photo, and Liani confirms it matches the one from the boathouse.

The realization hits everyone: Dr. Henson is likely in the dark water, and sometimes people don't come back from that.

Key Events

The group confirms Dr. Henson is missing after texts and calls go unanswered.
They split into search parties: narrator and Riki search the house, April and Van handle tours, Liani takes the Jet Ski to search the water.
The house search turns up nothing.
In the boathouse, April dives under the dock, gets her foot caught in netting, and is rescued by Riki.
April sustains cuts and loses her grandmother's necklace.
Liani returns without finding Dr. Henson, prompting the call to the police.
Two officers arrive and question the group; the last sighting was around 8 PM the previous night.
An officer searches Dr. Henson's room and finds her keys left behind.
A search boat with divers and a glass-bottom-boat operator begin searching the water.
A boater reports finding a purple paddleboard with a wave pattern near Mulligan Island, matching the missing one.
The group realizes Dr. Henson may have drowned.

Character Development

The narrator shows a mix of practicality and emotional observation.

She's methodical in the search, but she also notices Riki's appearance and her own attraction to her, even in a crisis.

This chapter deepens her internal conflict between focusing on the emergency and her personal feelings.

Riki emerges as a calm, decisive presence.

She warns April about the danger under the dock, then acts instantly to rescue her when she gets stuck.

Her bluntness (“I told you”) and her ability to stay focused under pressure highlight her competence.

April is impulsive and anxious.

Her decision to dive under the dock, despite the warnings, shows her desperation to find Dr. Henson, but it also puts her in danger.

Her loss of the necklace—a sentimental item—adds a layer of personal loss to the crisis.

Liani takes charge, organizing the search and making the call to the police.

She's pragmatic and clear-headed, but her grim expression when she returns from the water shows her worry.

Tom is concerned but also aware of the political implications—he uses a “professional tone” that suggests he's thinking about how this might affect his reelection campaign.

Van is more casual, chewing on his walkie-talkie antenna, but he's observant enough to notice the grad student Makoto lurking in the hall.

Themes, Symbols, or Motifs

Dark water as threat: The St. Lawrence River is described as wide, strong, and full of water.

The boathouse's dark, debris-filled under-dock area symbolizes the hidden dangers of the water.

The final image of Dr. Henson in that dark water reinforces the idea that the water is a place of disappearance and death.

Perception shift: The opening line—about the jump from “someone who can't be found” to “someone who is missing” being long and short at the same time—captures how a change in perception can alter the meaning of the same facts.

The group's understanding of the situation shifts from a temporary absence to a potential tragedy.

Left-behind belongings: Dr. Henson's keys, left in her bedside drawer, are a significant clue.

They suggest she didn't intend to leave the house, or at least not to drive anywhere.

The missing paddleboard, on the other hand, suggests she went out on the water.

The contrast between what she left and what she took becomes central to the investigation.

Paddleboard as evidence: The purple paddleboard with a wave pattern is a concrete object that ties the disappearance to the water.

Its discovery near Mulligan Island is the first hard evidence that Dr. Henson may have been on the water, and it shifts the search from a missing-person case to a likely drowning.

Why This Chapter Matters

This chapter is a turning point in the mystery.

It moves the story from a vague concern about Dr. Henson's whereabouts to a full-blown police investigation.

The discovery of the keys and the paddleboard provides concrete clues that will drive the plot forward.

The chapter also deepens the character dynamics, especially the narrator's growing attraction to Riki and April's vulnerability.

The search sequence builds tension, and the final revelation—that the paddleboard has been found—creates a sense of dread that sets the stage for the next chapter.

Study Questions and Answers

1. What does the discovery of Dr. Henson's keys in her room suggest about her disappearance?

The keys being left behind is significant because it implies she didn't intend to drive anywhere or lock up the house.

It also suggests she may have left in a hurry, or that she didn't plan to leave at all.

The officer's question about notes or messages hints at the possibility of suicide or a deliberate departure, but the keys complicate that theory—if she planned to leave, she'd likely take her keys.

This clue points toward an accident or foul play rather than a planned absence.

2. How does the narrator's perception of Riki change during the boathouse scene?

The narrator is already attracted to Riki, but in this chapter, she observes Riki's physical appearance in detail—her dark-blue lipstick, her blunt haircut, the way the light suits her.

When Riki jumps in to save April, the narrator notes that it was “absolutely hot as hell” and that she would dwell on it for a long time.

This moment combines the narrator's romantic feelings with a new appreciation for Riki's bravery and competence, deepening her emotional investment.

3. Why is the paddleboard's discovery near Mulligan Island so important to the investigation?

The paddleboard is the only physical evidence that connects Dr. Henson to the water.

Liani confirms it matches the one missing from the boathouse, which means Dr. Henson likely took it out.

Its location near Mulligan Island suggests she may have drifted or been carried there by currents.

The discovery shifts the search from a land-based missing-person case to a water-based recovery effort, and it strongly implies that Dr. Henson is in the water, possibly drowned.

This is the moment the group realizes the likely outcome.