Meer confirms that he always knew about Matilda and was excited to meet her. Matilda reflects on their lack of shared history and realizes Meer is the child Kingsley chose to raise. Despite this painful realization, she cannot resent Meer, who clearly wants a sister. She sees their shared blood as a connection.

Meer explains he only knew her name and that her mother appears in the Persephone painting. Kingsley thought knowing about her would benefit Meer’s imagination. Meer confesses he used to draw pictures of her in his sketchbook when lonely as a child. Matilda reveals she also keeps a sketchbook for game ideas, and they bond over this parallel habit. Both use drawing to process the world, like their father.

Matilda asks when Kingsley will return. Meer is evasive, saying Kingsley wants her there to experience the place and meet everyone. Pressed, he admits that Kingsley dislikes schedules and that they don’t know when he will be back. He defends their father as a genius who must live unconstrained to channel the muse. Though Matilda harbors resentments about Kingsley’s abandonment, she only expresses her desire to meet him. They discover they are both 18, with Meer slightly older, which delights him.

Approaching the castle’s back entrance, Matilda and Meer enter a screened porch functioning as a mudroom. The space is filled with shelving holding beach equipment, all labeled with weathered signs in June’s calligraphy and goofier ones made by Meer and Tatum as children. Meer comments that the household used to have more people but now consists of just the four residents plus Kingsley.

In the kitchen, they find June Sugawara standing on a footstool over a large vat of indigo dye. The kitchen is covered in tarps, with blue-dyed clothing hanging on lines throughout the room. Meer introduces June as his mother and explains that Kingsley invited Matilda.

June is irritated, asking about their family decision not to have visitors this summer. She questions whether Kingsley actually invited Matilda. When both Meer and Matilda insist he did, June remains skeptical about her staying. Meer urges his mother to blame Kingsley rather than him and to show her characteristic kindness. June looks up from her work for the first time and recognizes Matilda as Kingsley’s child.

June’s irritation vanishes, and she begins explaining her indigo dyeing project. She hands Matilda an apron, and all three work together in focused silence, wringing out fabrics and hanging them to dry.      

Matilda excuses herself to check her phone, finding no message from Kingsley. She texts him, saying she arrived safely, is glad to have met Meer, and notes that June did not know she was coming. When Meer removes his shirt to dye it, Matilda notices his torso is covered in Sharpie drawings.

Paul-David Brock enters the room, also shirtless and covered with more elaborate Sharpie art. He hugs Matilda enthusiastically when Meer introduces her as family. Matilda recognizes him as Sammy from the television show Men and Other Critters. Brock distances himself from that character, saying he had to leave Sammy behind completely. He credits Kingsley and June with helping him. As they work together tying Matilda’s henley for dyeing, June explains that Hidden Beach’s symmetrical architecture balances the chaos within Kingsley. Meer observes that when her shirt dries, Matilda will look like one of them. Overwhelmed by her long trip and everything she has experienced at Hidden Beach, Matilda passes out.

Matilda wakes on a velvet couch in a breakfast nook adjacent to the kitchen. Above her hangs one of Kingsley’s paintings, Cliffside Gothic, which depicts a family of five at a cliff’s edge: parents and three teenage daughters in white cotton. The eldest daughter stands barefoot with feet and fingernails black with ash, evoking Cinderella. June tells Matilda not to let the painting depress her.

June returns with a tray of dark brown bottles containing herbal tinctures. When Matilda asks what the herbs are, June assures her they will heal her and tells her to trust her expertise. The liquid tastes bitter and deeply rotten, but with encouragement from June and joking from Meer, Matilda drinks the entire glass.

Meer leads Matilda up Parchment Tower to the Iron Room on the fourth floor, carrying her duffel bag. As they climb, he shares how Kingsley used to comfort him during childhood nightmares by sitting beside his bed and having him describe the pictures on his closed eyelids until he fell asleep. When Matilda says Kingsley sounds like a good father, Meer responds that he is a great artist. When asked if Kingsley ever painted him, Meer describes the experience: Though posing is boring and Kingsley forgets he is a person, the finished painting reveals something from his soul.

After Meer leaves, Matilda searches for her phone and laptop to text her mother and Saar but discovers both devices are missing from her backpack. She recalls Meer mentioning they keep electronics locked up, accessing them only on Mondays and Thursdays, and she realizes that June must have taken her devices while she was unconscious. While unpacking, she overhears Brock and Tatum Cooper-Lee in the hallway. They confirm neither knew about her arrival. Tatum expresses concern about her presence, saying she will mess Meer up with feelings, and they should not add another person to their household.

Matilda goes downstairs for dinner but finds no one. The living room is minimalist but messy, with stained couches and old food remnants. Above the fireplace hangs Odysseus Flees, a Kingsley painting showing a tiny man in a speedboat on violent waves, escaping from a dead Cyclops on distant land. Matilda thinks about what she knows about Odysseus from the video game Killer Odyssey. The dining room is similarly messy with old dishes and trash.

In the orderly kitchen, the indigo project has been cleaned up and fabrics hung outside to dry. Feeling an urge to learn about her father, Matilda opens the refrigerator. It contains glass jars of homemade foods labeled in June’s calligraphy. In a crisper drawer, she finds small manila packets labeled with all the residents’ names, including four marked Matilda, surprising her since she just arrived. She opens one labeled Kingsley, and fine herbal powder spills everywhere.

Tatum appears in the doorway. Matilda recognizes him as her rude taxi driver from the airport. When she mockingly asks if the powder is drugs, he meticulously cleans the spill. The packets contain chia, herbs, and collagen; Tatum explains June had him make Matilda’s after she arrived, as a welcoming gesture. He sarcastically contrasts this hospitality with her snooping, and she storms outside.

Outside, Matilda finds Meer and Brock grilling steak near the cliff. June is too busy with her projects to join them for dinner. After dinner, Brock teaches them Mao, a card game where rules are not explained to new players. Matilda figures out the rules quickly while Meer remains confused. Later, Meer walks Matilda to the cliff edge and points out Beechwood Island in the distance. He reveals plans to take the boat there that night with Brock and Tatum to explore the burned Sinclair house. Despite her fear of trespassing on the private property where three teenagers recently died in a fire, Matilda feels kinship with Meer and agrees to go.

Tatum appears, climbing the stairs from the beach, dripping wet. Meer runs to him, saying his sister is here, but Tatum confirms they have already met. Tatum remains distant, saying he needs a shower and food. As he passes Matilda to reach the castle, she makes a sarcastic remark about his low energy, which he ignores.

In the Iron Room, Matilda reflects on how video games provide an outlet for rage. Unable to access her game Something Rotten because her laptop is locked up, she sketches a new game level idea featuring a chandelier monster. At 10:50, she goes to the garage where only Tatum waits, staring down the driveway.

They stand in awkward silence until Glum appears. Tatum plays fetch with the dog, and Matilda pets her, feeling instant love. Tatum calls Glum a terror because she defecates on the rug. He tells a disturbing story about once leaving a large pile of dog feces on the living room rug for five days to see how long the others would ignore it. Everyone pretended the toxic mess was not there. Meer and Brock finally appear, saying they were late because they accidentally fell asleep.

Despite his objections, Tatum agrees to go with them to Beechwood. They pull Vespas from the garage and walk them down the driveway so June will not hear. At the bottom, Meer and Brock suddenly speed away, leaving Matilda to ride behind Tatum.

The group arrives at Menemsha, a small fishing village with a marina. They find Kingsley and June’s white motorboat docked there. Meer steers them out of the harbor into open water.

In the dark ocean, Matilda feels overwhelmed by the vastness surrounding them, spiraling into thoughts of being adrift and nowhere. Tatum, sitting beside her, asks if she is motion sick. She lies, saying that she is fine. He says he loves being out at night because the infinity makes everyday problems unimportant. To steady herself, Matilda focuses on his profile in the moonlight, thinking about how his waist felt under her hands during the scooter ride. Beechwood Island appears slowly as a dark shape. Meer circles around to a long wooden dock in a cove. He cuts their lights.

After docking their boat, the group makes their way to the property. They stand before the ruins of the Sinclair house. Only the brick chimney and some beams remain standing; the rest is charred rubble. The area smells of firewood, charcoal, and chemicals. Brock, finding the scene too dark, leaves to search for the pool.

Tatum says they should not have come. Meer apologizes, admitting it feels sadder than he imagined. He explains that Harris Sinclair, a publishing boss from Boston, owned the house, and most of the family survived. Tatum announces he is leaving to find Brock. Meer realizes the burned house might upset Tatum because of his parents’ deaths. Tatum sharply explains to Matilda that his parents died in a fiery car crash while driving high. He softens toward Meer, saying coming was his own choice, then leaves to be alone.

Meer confesses his real reason for coming: he hoped seeing the ruin would be like entering one of Kingsley’s paintings and understanding his fiery imagination. He questions why things in their father’s work are always burning. Kingsley never discusses his childhood or family. Meer reveals he knew one of the victims, Mirren Sheffield, through social media. They had planned to meet but never did. He explains his social isolation due to homeschooling. Matilda confesses she has no friends either, and they bond over their loneliness.

They find Brock and Tatum playing tennis on a dimly lit court. Tatum explains they found equipment in an unlocked hutch containing a mini-fridge and, oddly, a lemon among the tennis balls. They play a chaotic game called Snowball, throwing balls and the lemon over the net while trying to keep their side clear. During the frantic game, Matilda stumbles and falls, scraping her palms and wrists badly.

The game stops. Matilda is overwhelmed by pain, exhaustion, and sadness, feeling like an outsider among these boys who all know each other. As the boys begin arguing about setting up another game, she slips away on the verge of tears, following a lit walkway to a different house.

She descends stairs to a small beach and washes her bloody hands in the stinging saltwater. Tatum finds her, saying they were worried. He gently inspects her scraped hands. Noticing her shivering, he pulls off his sweater and gives it to her. Matilda puts on the warm sweater and follows him back toward the dock.