Emmeline is a young girl raised in complete isolation on an island off the coast of British Columbia. She possesses a highly sensitive sense of smell, able to detect the emotional states of others through their natural aromas. She spends her days learning from her father and studying her beloved book of fairy tales. Deeply curious and sheltered, she initially accepts her father's explanations about their world without question. When circumstances force her to leave her isolated home, she works to adjust to the unfamiliar modern society of Secret Cove.

Fisher is a quiet, red-haired boy who lives in the fishing town of Secret Cove. As the son of a frustrated fisherman, he frequently misses school and maintains a calm, observant demeanor that sets him apart from his peers. He forms an immediate, unspoken bond with Emmeline when she enrolls in his class, and the two spend their afternoons talking in a large nest made of branches on the resort grounds.

John is a prominent but obsessive scientist who lives alone with his daughter on a remote island. He dedicates his time to a sleek, silver machine used to capture and bottle the specific aromas of the island environment onto thin strips of paper. Protective and controlling, he structures Emmeline's world entirely around his rules and the stories he tells her.

Victoria is the principal architect of Inspire, a global perfumery headquartered in Vancouver. She specializes in using carefully constructed scents to influence consumer behavior and boost sales, such as streaming the scent of coconuts into a bar to sell more rum. She possesses a calculating mind for business and relies on an extensive collection of specialized aromas to manipulate environments.

Henry is a practical, hardworking man who runs a modest summer resort in the coastal town of Secret Cove. He periodically delivers necessities like flour and rice to the remote islands in the archipelago, serving as an early link to the outside world. He eventually offers Emmeline a place in his home when she must transition to modern society.

Colette operates the Secret Cove Resort alongside her husband. She works tirelessly to maintain the ramshackle cottages and keep the business running when a television feature brings a sudden influx of tourists. She provides a welcoming presence for Emmeline, helping her transition into a completely foreign society and enrolling her in school.

Martin is a deeply frustrated fisherman in Secret Cove. He works one of the last fishing vessels in the area and struggles with an array of personal and professional disappointments. He carries an aura of stale smoke and gasoline, creating a tense atmosphere in his household.

Cleopatra is a lively pet goat who provides Emmeline with her first real companionship on the island. She accompanies Emmeline on her bold explorations of the woods and the forbidden lagoon, giving the young girl the courage to venture further from the cabin.

Claudia is a professional scent designer at the Inspire perfumery. She treats perfume creation as a mathematical formula, relying on mental databases rather than organic intuition. She guards her position in the company fiercely and initiates a harsh training regimen for newcomers.

Rene is an older, experienced researcher at Inspire who focuses on recreating scents that are disappearing from the modern world, such as typewriter ribbons and virgin forest rains. He serves as a quiet historian within the bustling corporate environment, retaining knowledge of the company's early days.