Blood Sugar

Ruby, a thirty-year-old licensed psychologist living in Miami Beach, narrates the story of her life from a police interrogation room, where she stands accused of murdering her husband. The novel moves between this interrogation and Ruby's past, revealing that four people have died in her proximity. She killed three of them, but not the one she is accused of.

At age five, Ruby commits her first murder. She watches seven-year-old Duncan Reese struggling in the Atlantic Ocean while his inattentive parents sit on the shore. Instead of helping, Ruby grabs Duncan's ankle and holds him underwater until his body goes limp. Duncan had been a relentless bully who tormented Ruby's older sister, Ellie, dropping insects on her and ripping a lock of hair from her scalp. Ruby's parents, whom she calls "submarine parents" who expected their children to handle problems independently, did not intervene. As a child, Ruby also brought a wounded bird to a local bird sanctuary, a refuge she returns to throughout her life. Duncan's death is ruled accidental. Ruby waits for guilt to arrive, but it never does.

Twenty-five years later, Detective Keith Jackson, a veteran homicide detective, places four photographs on the table, each depicting someone who died near Ruby. She tells Jackson she knew Duncan and that his drowning was tragic, then mentally reviews every event that led her to this moment.

After Duncan's death, Ellie's confidence returns. At fifteen, with Ellie away at college, Ruby fills the void with cocaine. She frequents Kremlin, a small gay club on South Beach, where she befriends Jesula, a Haitian immigrant who works in the bathroom selling candy. Ruby is the only person who treats Jesula as visible, once buying her a lollipop in a gesture that will prove significant years later. One night Ruby encounters Duncan's devastated mother in a club bathroom, scraping an empty cocaine vial. The sight gives Ruby clarity, and she never uses drugs again.

At sixteen, Ruby commits her second murder. Serving as the designated driver on Halloween, she brings her drunk friends, including Hannah Vale, to bed at Hannah's house. Hannah's father, Richard Vale, corners Ruby, forces a kiss, and gropes her. Knowing Richard has a deadly peanut allergy, Ruby chews peanut M&M's and forces the candy into his mouth. He dies of anaphylaxis. Ruby collects the evidence and buries it at the bird sanctuary. Police rule the death accidental.

At Yale, Ruby majors in psychology and forms a deep platonic friendship with Roman Miller, a pre-law student. The friendship shatters during senior year when Roman reveals Ruby's affair to win over a girl they both know. Ruby is devastated and stops speaking to him. Despite their estrangement, Roman later names Ruby as his alibi when caught cheating on an exam. Ruby lies to the dean to save him. Roman leaves a note: "I owe you."

Back in Miami for her doctoral program, Ruby reconnects with her therapist, Dr. Alisha Goldman, who has relocated to Miami. She rescues a kitten from a garbage can, naming him Mr. Cat, and takes over sessions with a court-ordered client she calls "the Witch," a rageful woman named Evelyn W. She meets Jason Hollander, a cameraman from Georgia who has type 1 diabetes, at a lamp-repair shop. Their unconventional courtship begins: Jason gets to know Ruby through her opinions rather than her biography.

Ruby commits her third murder by killing the Witch. She positions herself at a crosswalk as a delivery truck approaches and steps off the curb. The Witch, staring at her phone, senses the movement and follows. Ruby steps back; the Witch is struck and killed. The death is ruled accidental.

Ruby and Jason marry in Key West, but his mother, Gertrude, is a toxic presence. Gertrude abandoned Jason at age two and reconnected only when he was self-sufficient. Ruby identifies her as a "cobra" abuser: sly, manipulative, and relentless. When Gertrude kicks Ruby during a visit to announce the engagement, Jason cuts his mother from his life.

Three months after the wedding, their rescue dog, Kangaroo, dies suddenly. Ruby copes by immediately removing all of the dog's belongings, the same mechanism she will use after Jason's death. Mr. Cat develops diabetes, and his insulin vials sit beside Jason's in the refrigerator, a detail that will fuel the prosecution's theory. Ruby also opens her own practice and takes on Gabrielle R., a young writer with PTSD who blames herself for the death of a date who was shot shielding her during a restaurant shooting.

Ruby participates in a weeklong relaxation study and returns home deeply at ease. For the first time, she sleeps through Jason's glucose monitor beeping in the night. She wakes to find Jason cold and lifeless, dead from fatally low blood sugar during sleep.

The coroner finds no foul play, but Jackson visits Ruby's home and notices Jason's missing belongings. Ruby discovers Jackson is a homicide detective and calls Roman, now a criminal defense attorney. Roman identifies Ruby's $900,000 financial gain as motive and realizes Gertrude is driving suspicion against her.

Jackson seizes Mr. Cat's insulin as evidence. Roman discovers surveillance footage from the crosswalk where the Witch died and ensures it cannot leak to the press. A grand jury hears the prosecution's theory: Ruby injected Jason with insulin while he slept, then had him cremated to prevent re-examination. The most damaging testimony comes from Jesula, now Ruby's housekeeper, who falsely claims Ruby callously discarded Jason's belongings while treasuring their dead dog's mementos. In truth, Ruby grieved identically for both. Ruby is indicted for first-degree murder.

Jackson arrests Ruby at her office in front of Gabrielle, deliberately destroying her professional reputation. Roman secures her release on $2 million bail. The media dubs Ruby "the Purple Widow." She loses her practice, her friendships, and even Alisha, who suspects Ruby "had a hand" in the other three deaths and ends their therapeutic relationship.

Ruby tracks down Gabrielle to share information she overheard at the police station: The man who died protecting Gabrielle was an undercover FBI agent targeted for assassination. His death had nothing to do with Gabrielle. Ruby considers this revelation her most important act as a therapist.

Three days before trial, Jesula confesses to the judge that Gertrude bribed her with $10,000 and threatened her with deportation to coerce false testimony. Bank records confirm the bribe, and all charges are dismissed. Roman also produces a video of Gertrude telling a charity representative that her son died of diabetes, confirming on camera that Ruby did not kill him.

Roman then reveals he orchestrated the scheme. He instructed Jesula to approach Gertrude for bribery money, knowing Gertrude's malice would guarantee compliance. Jesula delivered false testimony so she could later recant, demolishing the case from within. Her willingness to risk everything traces back to Ruby's small act of kindness at Kremlin years earlier.

Ruby uses Jason's life insurance to establish a college fund for Jesula's son. She and Ellie move to Santa Monica and begin new lives. Ruby passes the California licensing exam and opens a new practice. She quietly establishes a private rule: one murder per decade, maximum. Watching her young niece being bullied, she resolves to give the girl tools to protect herself, "all the while keeping an eye out for my own bullies to slay."