This story is told through many concise sentences, which are often out of sequence, but this review will attempt to tell the story in a linear fashion. Cadence Sinclair Eastman is almost 18. She lives with her mother in Vermont. Her father left the family when Cadence was 15. His leaving shattered her world.
Cadence is the granddaughter of Tipper and Harris Sinclair, wealthy elite of New England. Every summer Cadence spends her vacation on an island off Massachusetts, which is owned by her grandparents. She revels in the freedom of the island and loves to spend time with her cousins — Johnny and Mirren — and their family friend, Gat. Johnny’s mother’s boyfriend is Gat’s uncle. Cadence instantly formed an attachment to him when they met roughly nine years earlier.
Although welcomed to the island every summer, Gat never feels truly at ease because he is of Indian decent and can tell that the Sinclair grandparents do not approve of him. The four grow up together each summer and call themselves “the Liars.”
Cadence and Gat start a more romantic relationship during the summer of their 14th year, but when Cadence returns the following year, Gat has another girlfriend back home. The news crushes Cadence, as her father had just left the family that month. But Gat cannot deny his feelings for Cadence. They rekindle their romance, this time on a more physical level. This 15th summer is the first one without Tipper. Cadence’s grandmother had died, and the main house feels empty without her. Harris seems weaker without his wife, and the children are instructed to not mention their grandmother around him so as not to upset him.
At some point, late in the summer, Cadence recalls going for a swim in the evening, without her cousins or Gat. Her mother found her later on the beach, shivering and numb. Cadence is taken to the hospital, suffering from hypothermia, respiratory problems and some kind of head injury that didn’t show up on the brain scans. She becomes depressed after her mother takes her back home to Vermont and Gat doesn’t contact her to find out how she is recuperating. Her cousins do not answer her emails either. A few weeks after the accident, Cadence develops debilitating migraines that cause her to vomit and pass out. The doctors can find no reason for her problem, but give her prescription medication to help with the pain.
The following summer, still sick and trying to recover from an accident she cannot remember, Cadence’s father insists she accompany him to Europe rather than go to the island. She spends most of the trip vomiting in the bathrooms of hotels and museums. She tries to email her cousins about her adventures, but they do not respond.
When she returns, Cadence begins two projects. In one, she continually rewrites the story of King Lear and his three daughters. Her stories begin to pepper the book and seem to reflect how she views her grandfather and how he treats Cadence’s mother and aunts. Cadence also begins to give away one possession every day. She starts by mailing her cousins items she knows they liked. She gives away her bed pillow, old pictures, toys and books as well.
Cadence’s father wants to take her to Australia in the summer, but she begs to go back to the island. Her grandfather comes to visit before a decision is made. He seems thinner and more distracted. One afternoon he goes into the garden. Even though Cadence warns him not to, he picks three peonies and gives them to her to ask for forgiveness. After her grandfather leaves, Cadence’s mother calls to cancel the trip to Australia. It is decided that Cadence will go to the island for a month and then visit her father in Colorado.
Once Cadence arrives on the island, she discovers her grandfather has renovated his old house. Instead of the rustic, turreted mansion, a sleek modern Japanese-inspired home sits on the hill. Cadence is sad to see the old maple tree with its tire swing has been torn down as well. She learns that the Liars will share one of the houses together, away from the families. The others tell her they won’t even go up to the main house for dinner this year. She would like to join them, but her mother insists she sleep at their house and eat dinner with the family.
With only four weeks on the island, Cadence is determined to discover what happened to her two summers earlier, but her family is reluctant to talk to her about it. Even the little cousins have been forbidden to discuss what happened. Cadence spends the days with the Liars, but they do not give her any information either.
As the weeks progress, Cadence’s memory begins to return, but it is in glimpses and out of order. She can remember her mother and the aunts fighting with Grandfather about his estate. He acted like King Lear, trying to determine which daughter loved him the most and deserved more of his estate when he died. The mothers tried to get the children involved in the fight, each asking their eldest to talk to Grandfather into loving them the most. Cadence’s mother tried to get her to break up with Gat so as not to aggravate Grandfather, who did not like her taking up with a dark-skinned boy.
As the memories come back, Cadence recalls that what she originally remembered as a bonfire was actually her grandfather’s house burning. Then she recalls that she and the other Liars set the fire. Her grandfather’s beloved golden retrievers were killed in the blaze. She and the Liars had gotten drunk when the other adults took the younger children to the mainland to see a movie. The teenagers were all angry at how the adults were behaving — bickering over Grandfather’s money and possessions. In their stupor, they thought it would teach the adults a lesson if they burned down the main house so that no one could inherit it.
Tragically, they split up within the house, each taking a floor to set alight. Gat took the basement; Cadence — the main floor; Mirren and Johnny — the upper two floors. Cadence misjudged how fast the library books would burn when doused with gasoline and the fire quickly spread up to the ceiling and across the floor. She managed to escape but the others did not. For the past two years, her mind has been protecting her from the reality that her beloved Liars are dead.
Cadence says goodbye to the ghosts of Johnny, Mirren and Gat (whom she thought were real since she came that summer). She contemplates the past with a heavy heart. She thought her mother and aunts were getting along this summer because her grandfather had renovated the old house. Instead, she realizes they are clinging together in their grief. But she believes they will all eventually come through the tragedy as better people.