Nadia is a fourteen-year-old former circus performer of mysterious origins. She is an orphan who grew up under the unloving care of a ringmaster, which left her with a deep distrust of adults and a fierce, independent streak. She is stubborn, short-tempered, and strongly opinionated, particularly about her strict vegetarianism and her absolute opposition to killing any living creature. She wears a blue jeweled pendant called the Blue Water, which she possesses without understanding its true significance, and she is pursued by jewel thieves who seek the pendant. Despite her prickly exterior, Nadia is deeply insecure and fears betrayal from others. She is kind-hearted, gentle with animals, and has the ability to understand animal speech, a gift that hints at her extraordinary heritage.

Her central motivation is to discover her own origins and the secret of the Blue Water. As the story unfolds, she becomes embroiled in a global struggle between Captain Nemo’s crew and the Neo-Atlantean forces, who aim to dominate the world. Her role is that of the main protagonist and the key to unlocking the legacy of Atlantis, as she is later revealed to be the last pure-blooded Atlantean princess. This revelation explains her innate connection to ancient technology and her ability to activate Atlantean machines.

Nadia’s key relationships shape her growth. Her bond with the young inventor Jean Roque Lartigue begins with mutual annoyance but deepens into trust and love, teaching her about respect, friendship, and faith. She also develops a strong attachment to the orphaned girl Marie and her lion companion King, forming a chosen family. Her initial adversarial dynamic with the Grandis gang shifts as they become allies, and she gains a grudging respect for Captain Nemo, though her pacifist beliefs often clash with his methods.

Throughout the series, Nadia undergoes significant development. She starts as a defensive, angry runaway but gradually learns to open up, accept help, and rely on others. Her experiences force her to confront her moral convictions and her fear of abandonment, ultimately leading her to embrace her identity and her place in a larger world. By the epilogue, she has married Jean and they have a child, symbolizing her journey from isolation to connection.

Notable abilities include her acrobatic skills, honed from her circus training, her talent for communicating with animals, and her latent Atlantean powers, which allow her to command advanced technology. The Blue Water itself amplifies her connection to Atlantis and serves as a key artifact in the conflict. Nadia’s combination of vulnerability, fierce independence, and moral clarity makes her a compelling and memorable heroine.