Nina Martin, portrayed by Nathalia Ramos, left the show after the second season due to her character completing her quest and the actress choosing to focus on her studies.
In the context of the show, “House of Anubis,” Nina Martin is an American student who comes to Anubis House, a British boarding school, and quickly becomes embroiled in the mystery surrounding the house and its hidden secrets. Over the first two seasons, Nina is revealed to be the “Chosen One,” a key figure in an ancient prophecy related to the hidden treasure of the house and the mysteries of the Egyptian god Anubis.
Throughout the first season, Nina discovers the Eye of Horus locket, which allows her to solve various puzzles and ultimately find the Cup of Ankh, an ancient Egyptian artifact. In the second season, her quest continues as she searches for the Mask of Anubis and the seven pieces of the Ankh. With the help of her friends, known as “Sibuna,” Nina successfully navigates the dangers and challenges posed by the house and its protectors.
However, at the end of the second season, Nina’s story arc reaches a natural conclusion with the completion of her quest. Behind the scenes, Nathalia Ramos decided not to return for the third season, as she wanted to focus on her college education. Consequently, the show’s writers wrote her character out by explaining that Nina could not return to Anubis House because it was too dangerous for her to stay—the gods had warned that her presence would put her friends in peril due to the power of the Osirian, her protector, and love interest, Eddie Miller.
Nina’s absence is felt in the third season, and she is occasionally mentioned by the other characters, but the show continues to explore new mysteries with the remaining students and some new faces.