Savannah is a seventeen-year-old girl struggling with severe anxiety and isolation following the death of her older sister, Poppy. She uses her studies as a distraction and finds social interaction overwhelming. Reluctantly joining a five-country grief therapy trip, she brings along an unread journal left to her by Poppy. She possesses a quiet, introverted nature but deeply observes the people around her.

Cael is an eighteen-year-old former hockey player who carries intense anger following the tragic death of his older brother, Cillian. He covers himself in tattoos to distance himself from his past and pushes away his family and friends. Forced onto the international therapy trip, he initially refuses to participate in group activities. He uses aggression as a shield but shows flashes of gentleness when interacting with Savannah.

Dylan is an outgoing teenager participating in the international grief therapy trip. He presents a boisterous and friendly front, immediately trying to make others feel welcome. Underneath his energetic personality, he carries the heavy burden of losing his best friend, Jose. He uses humor and conversation to keep his true sadness at bay.

Lili is a teenager attending the grief therapy trip after losing both of her parents in a boating accident. She actively participates in the group's sessions and activities. She quickly bonds with another girl on the trip, Jade, finding comfort in their shared experiences of profound loss.

Jade is a teenage girl processing the death of her mother and brother from a car accident. She lives with her surviving father and joins the therapy trip to find ways to cope. She forms a fast friendship with Lili, sticking close to her as the group travels from country to country.

Travis is a teenager participating in the therapy trip as the sole survivor of a school shooting that killed eleven of his friends. He has a strong interest in sports data and tries to use this hobby to connect with others. He initially struggles to break through Cael's aggressive exterior but remains polite and eager to engage with the group.

Poppy is Savannah's deceased older sister who died of cancer four years ago. Before passing, she wrote a journal specifically for Savannah, filling it with advice, affirmations, and comfort. She maintained a remarkably positive outlook on life and death, wanting her family to continue living fully. Her memory serves as a guiding force for Savannah.

Cillian is Cael's older brother who died in a fatal car crash a year before the main story begins. He was a talented hockey player who constantly encouraged Cael's athletic dreams. His sudden death leaves a massive void in his family and sparks Cael's intense anger and confusion. He leaves behind a brief, cryptic note on a hockey ticket.

Ida is Savannah's younger sister, characterized by a sunshine-like, boisterous personality. Despite dealing with her own grief over losing Poppy, she takes on a supportive role for Savannah. She actively encourages Savannah to attend the therapy trip and pushes her to open up to new experiences and potential romances.

Leo is a therapist co-leading the five-country grief trip. He brings personal experience to his profession, having lost his own father to suicide when he was a teenager. He pushes the group hard during physical and emotional exercises, specifically keeping a close eye on Cael's volatile behavior. He believes strongly in confronting pain directly.

Mia is a therapist who co-leads the international trip alongside Leo. She takes a gentle, guiding approach, often conducting one-on-one sessions with the teens. She provides the group with therapy journals and encourages them to use writing as a tool to communicate with their lost loved ones.

Rune is Poppy's devoted boyfriend who travels the world as a photographer after her death. He regularly visits Poppy's grave to leave photographs of his travels, keeping her involved in his life. He maintains a connection with Savannah, serving as an example of someone who carries his love forward despite immense loss.

Stephan is Cael's childhood best friend and former hockey teammate. He witnessed the immediate aftermath of Cillian's fatal car crash alongside Cael. He desperately wants to reconnect with his friend, but Cael actively pushes him away to avoid the painful memories Stephan represents.

Jose is Dylan's deceased friend whose death prompts Dylan to join the grief trip. He was killed by a drunk driver. His passing leaves Dylan completely devastated and struggling to honor his memory while keeping the true depth of their bond a secret from their families.

Rob is a therapist at Savannah's local treatment center in Georgia. Recognizing that Savannah's anxiety prevents her from participating in traditional group settings, he suggests the international grief trip. He pushes her to realize that she needs to learn how to function independently before leaving for college.

Savannah's father struggles with his own grief following his eldest daughter's death. He experienced months of severe anger before slowly returning to a state of normalcy. He drives his daughters to the airport, expressing hope that the therapy trip will help Savannah heal.

Savannah's mother is deeply traumatized by the loss of her child. She provides constant comfort to Savannah in the immediate aftermath of the tragedy. She fully supports Savannah's decision to travel abroad, assuring her that Poppy is watching over her.

Cael's father is a police officer who takes a firm stance on his son's deteriorating mental health. Frustrated by Cael's destructive behavior and apathy, he mandates the therapy trip. Despite his stern approach, he desperately loves his son and attempts to maintain contact while Cael is away.

Cael's mother worries constantly about her son's refusal to engage with his future after graduating high school. She tries to remind Cael about his college hockey prospects, but her comfort is aggressively rejected. She stays in contact with the therapists to receive updates on Cael's progress.