Rocky is a writer, mother, and wife living in Western Massachusetts who struggles with severe anxiety and hypochondria. Her daily existence revolves around a frustrating medical odyssey as an unexplained rash spreads across her body. Simultaneously, she becomes obsessively fixated on investigating a local teenager's death in a freight train collision. Deeply tied to her family, she often expresses her intense love through the preparation and sharing of food to manage her catastrophic thinking.

Jamie is Rocky and Nick's adult son, known for his agreeable, friendly, and good-natured personality. He works as a junior analyst in New York for Dickens, a massive corporate consulting firm. He maintains a warm connection with his family in Massachusetts, standing in contrast to the intense anxiety experienced by his mother and sister.

Nick is Rocky's husband and a physical therapist with a calm, practical demeanor that sharply contrasts with his wife's anxiety. He provides a steady, grounding presence in the household, whether he is rewiring appliances or making popcorn. His tendency to downplay worst-case scenarios sometimes clashes with Rocky's hypochondria, but he prioritizes family unity above all.

Willa is Rocky and Nick's daughter who works in a lab studying fruit fly brains. Like her mother, she experiences generalized anxiety disorder, making her acutely sensitive to emotional undercurrents and easily distressed by nearby tragedy. She serves as the family's uncompromising moral compass, viewing situations with firm ethical clarity.

Dad is Rocky's recently widowed father who lives in an apartment on her property. Though he displays a cranky exterior and maintains a litany of minor complaints regarding temperature and food, his cantankerousness masks a profound grief over the loss of his wife. He is deeply integrated into the family's daily life, offering both comic relief and a connection to the past.

Miles is a young man who dies in a tragic collision between his car and a freight train at a local crossing. Though he is deceased before the narrative begins, his lingering digital footprint shows he was active in a community dance group. His death serves as the catalyst for widespread community grief and prompts Rocky's obsessive online research into the accident.

Christine is the grieving mother of Miles Zapf. She processes her profound loss publicly online, refusing to accept early narratives that her son's death was a simple accident or a suicide. Her raw, digital presence forces the local community to confront the human cost of the tragedy.

Maya is Jamie's wife, who works as the director of ocean life at the Museum of Natural History. She acts as a supportive partner to Jamie and gently attempts to mediate tension during difficult family gatherings, bringing a career-driven and perceptive energy to the family dynamic.

Jo is Rocky's longtime friend who offers a supportive and humorous escape from the intense anxiety of daily life. The two share moments of levity, enjoying outdoor trips and inside jokes that help Rocky step away from her health fears.

Davey is Jo's husband and an emergency room doctor. He serves as a reliable medical resource for Rocky's family, providing vital remote assistance and advice during moments of acute health panic.

Chris is Miles Zapf's grandmother and Christine's mother. She takes to social media to mourn her grandson, occasionally sparking friction with her grieving daughter over the public and accusatory nature of her posts.

Ruby is a teenage girl whom Willa meets on a dating app. She joins Willa on Halloween, sparking a promising new romantic connection that brings a moment of brightness to the family's autumn.

Sunny is Willa's friend who joins her in lighthearted activities. She brings a burst of energetic youthfulness into Rocky's kitchen while crafting decorations.

Dr. Strange is Rocky's dermatologist who performs her initial skin biopsy. He approaches his work with an unsettling enthusiasm for potential skin diseases and a habit of telling inappropriate stories during medical procedures.

Chicken is one of the family's cats. He is an affectionate pet who often demands attention, purring and drooling on Rocky's chest while she reads in bed.

Angie is the family's kitten, offering a cute and comforting presence in the household. She frequently sleeps curled near Rocky's pillow or lounges on the bed with Willa.

Angus Beef is Jamie and Maya's pet cat in New York. He serves as a point of connection for Rocky when she checks her family's social media accounts from afar.