Daniel is a charismatic, middle-aged linguistics professor originally from New York. He lives a secluded life in Ireland with his wife, Claudette, and their younger children, having lost contact with his older children in California. He is deeply devoted to his family but harbors heavy guilt over a decades-old secret involving his college girlfriend. His professional fascination with the evolution of words sharply contrasts with his personal inability to communicate his own emotional pain.

Claudette is a former international movie star who faked her own disappearance to escape the pressures of fame and an unfaithful partner. She now lives entirely off the grid in rural Ireland, fiercely protecting her privacy and her children. Claudette possesses a changeable, highly protective nature, viewing the outside world as a constant threat to her domestic peace. Her hermitage provides stability but isolates her from society.

Ari is Claudette’s eldest child from her relationship with a Swedish film director. As a young boy, his severe stammer causes him great frustration, but Daniel’s patient approach to his speech impediment forms the foundational bond of their blended family. As he grows, Ari develops into an intelligent, highly observant student who acts as a stabilizing force for his younger siblings.

Niall is Daniel’s eldest son from his first marriage. He suffers from severe eczema, a condition requiring intensive and painful treatments that set him apart from his peers. Despite spending much of his childhood separated from his father by a bitter divorce, Niall maintains a profound connection with Daniel, sharing his father's analytical mind and quiet intensity.

Phoebe is Daniel’s teenage daughter from his first marriage. Growing up without her father’s daily presence, she experiences intense moments of psychological dissociation, feeling as though she is split into two places at once. This emotional distance leads her to push away true friends and experiment with dangerous crowds, though she fiercely desires a genuine connection with Daniel beneath her outward anger.

Marithe is Daniel and Claudette’s daughter, raised in the sheltered, rural environment of their Donegal home. She is highly perceptive and easily absorbs the languages spoken around her, notably French and Irish. Her sharp observation skills occasionally expose the hidden tensions within her family’s secluded lifestyle, causing her deep anxiety.

Nicola is an established academic and Daniel’s former college girlfriend in the United Kingdom. She possesses a brilliant mind and a striking appearance but struggles privately with a severe eating disorder. Nicola and Daniel shared an intense, complex relationship complicated by a difficult pregnancy, and her memory casts a long, traumatic shadow over Daniel’s present life.

Timou is a successful Swedish film director who originally discovered Claudette and cast her in his movies before starting a romantic relationship with her. His repeated infidelity and chaotic lifestyle ultimately drove Claudette to flee with their son. Years later, he maintains a highly defensive posture regarding her disappearance, insisting she left the industry, not him.

Todd is Daniel’s former flatmate from his university days in the UK. He was present on the chaotic night Daniel last saw Nicola and holds crucial, hidden information about the aftermath of that evening. A former small-time drug dealer who eventually becomes a secondary school teacher, his estrangement from Daniel represents the heavy cost of their shared past.

Lucas is Claudette’s brother, living a quiet life in Cumbria. He serves as Claudette’s primary connection to her past, helping conceal her identity by legally owning her Irish property. He provides a grounded, practical counterpoint to his sister’s eccentricities and acts as an anchor for her during moments of crisis.

Maeve is Lucas’s wife. She endures physically and emotionally painful fertility treatments before ultimately pursuing international adoption. She finds unexpected comfort and practical parenting guidance from Claudette during her moments of deepest insecurity.

Pascaline is Claudette and Lucas’s mother. She frequently speaks French with her daughter, deliberately excluding Daniel from their conversations. She views Daniel with suspicion, believing him to harbor a dangerous, self-destructive streak that threatens her daughter's hard-won peace.

Teresa is Daniel’s late mother. She raised four children in Brooklyn while helping run her husband's family store. Though entirely devoted to her domestic life and her children, she quietly held onto the memory of a secret, unrequited love, preserving a small piece of her inner identity.

Paul is Daniel’s father, a practical man who runs a family store in New York. He struggles to connect emotionally with Daniel, especially in the chaotic aftermath of Teresa’s death, leading to a decades-long estrangement between father and son.

Lenny is Timou Lindstrom’s assistant. He manages the daily logistical chaos of Timou’s life, including delivering messages, organizing security, and handling the awkward fallout of his employer's affairs. He longs for the simplicity of his previous life in New York.

Calvin is Daniel and Claudette’s youngest son, raised entirely in the rural isolation of their Donegal home. He enjoys the simple, nature-focused life his parents have constructed away from the public eye.

Rosalind is an older traveler whom Daniel meets in South America. Having recently discovered her husband's long-term betrayal, she possesses sharp insight into fidelity and regret, offering Daniel vital perspective on how to manage his own mistakes.

Johnny is a man from Teresa Sullivan’s past in Brooklyn. He represents a powerful, unspoken romantic connection that Teresa keeps entirely separate from her domestic life, symbolizing the quiet internal lives people maintain behind their public roles.

Suki is Todd’s girlfriend and flatmate during Daniel’s college years in the UK. She shares the cramped attic apartment dynamics and acts as a witness to Daniel's increasingly complicated romantic life before he leaves for America.

Zhilan is Lucas and Maeve’s adopted daughter from China. Her arrival tests Maeve's confidence as a new mother but ultimately expands the family circle.

Myrna is Paul Sullivan’s second wife and Daniel’s stepmother. She attempts to offer Daniel practical advice when he returns to New York, representing the changes in his family home that he has actively avoided facing.