Mermaid Princess Amelia – Best Mermaid Book Series For Teenagers

Otavio Gandara is the third founder of the Underground, a figure who left the institution after his mermaid wife returned to the sea. He is the father of Vitor Gandara, the gangster who runs the Lower Underground. Otavio’s decision to leave was driven by personal loss—his wife chose the sea over the land, and he could not reconcile himself to that abandonment. He retains ownership of the locked area of the Underground, and Knossa Oligaris admits that she has no authority over his use of it.

Otavio has no on‑page presence; he is a figure from the past, a man whose grief led him to withdraw from the community he helped build. His son Vitor inherited his property and his connections, transforming the locked area into a criminal enterprise. Otavio represents the pain of separation between land and sea—a theme that runs throughout the novel—and his legacy is both the Underground and the shadowy Lower Underground that operates beneath it.