Kathryn is a history and music teacher in Ely, New Hampshire. She is thrust into a disorienting mourning process when her pilot husband dies in an explosion over the Atlantic. Raised by her grandmother following her parents' turbulent marriage and early deaths, Kathryn prefers order and predictability. Her desire to maintain control is tested as investigators probe the crash and she discovers unfamiliar notes and receipts in her late husband's pockets.

Jack is a 48-year-old pilot for Vision Airlines whose plane crashes off the coast of Ireland, leaving behind intense media speculation. He possesses a love for risk and spontaneity, characteristics that contrast sharply with his wife's need for security. He has distinctive two-toned eyes, a physical trait he passed to his teenage daughter.

Robert is a representative for the pilot's union who steps in to help Kathryn field calls from the press and manage the initial crash investigation. He projects a calm, observant demeanor that reminds Kathryn of a World War II codebreaker. He used to play the piano and provides a steadying presence in Kathryn's home, though his professional duties occasionally conflict with his personal support.

The 15-year-old daughter of Kathryn and Jack. She inherited her father's distinctive eye color and shares a deep closeness with him. She confronts the tragedy directly, demanding honesty over comforting platitudes from the adults around her. Her blunt reactions force her mother to recognize the complex ways teenagers process profound loss.

Kathryn's 78-year-old paternal grandmother who acts as her surrogate mother. A pragmatic woman who wears baggy jeans and loose sweaters, Julia dispenses blunt wisdom drawn from her own experiences with tragic family losses. She acts as an anchor for the household, recognizing when Kathryn and Mattie need space from each other.

A woman living in London whose name and contact information Kathryn discovers among Jack's left-behind belongings. Her life, marked by colorful decor and comfortable confidence, stands in sharp contrast to Kathryn's structured world. Her existence raises pressing questions about how Jack spent his time during overseas layovers.

The priest at the local Catholic church in Kathryn's community. He assists the family in organizing a successful memorial service that honors Jack despite the intense media scrutiny surrounding the crash.

A four-year-old girl living in London. She crosses paths with Kathryn during her search for answers overseas.

Jack's mother and the namesake of his teenage daughter. Her current residence in a Minnesota care facility surprises Kathryn during the investigation.