The Invisible Girl

Seventeen-year-old Julia is enjoying Cárdena's local festivities with her friends while her classmate Aurora has a secret date. The next day, a body appears at the high school. Julia's father Miguel Ángel is the Civil Guard lieutenant in charge of the case, but Julia also starts a parallel investigation in secret. Everybody is a suspect, and Julia discovers something disturbing.

The press is already talking about "The Compass Killer" due to one of the objects found next to the body. The police question the victim's friends and relatives and arrest the primary suspect. However, they can't find conclusive evidence. Julia continues her investigation, and someone blackmails her friend Patri. Julia's handsome classmate Iván is called in for questioning, and he asks for Julia's help in confirming his alibi. Will she do it?

While some people don't attend Aurora's funeral, a few of the mourners behave oddly at the ceremony. The interrogations continue, but the murder weapon has yet to appear. Patri is starting to get more anxious. Iván tells Julia his version of the events as well as an important secret. Someone sends Julia a riddle written on a chessboard. Can Julia prevent what's about to happen?

The serial killer hypothesis gains traction as a second body appears on the streets of Cárdena. There's a vigil for both deaths. The police continue their investigation and find new clues. Julia discovers the riddle she's been sent is an acrostic, and she deciphers a disturbing message, I know who killed her.

A traditional competition is held in Cárdena where several male pigeons are set loose after a female to breed. Some of the objects found next to Aurora's body belong to teachers from the high school, and this creates tension in the town. Julia discovers the riddle is based on a famous chess match, and Miguel Ángel leaks a bit of false news to make the killer nervous.

In despair, the town decides to organize a procession of the Virgin Mary to invoke her protection, but a third body appears. Miguel Ángel discovers several secrets that are relevant to the investigation. Julia solves the chess riddle and surprisingly unmasks the person behind the fake profile. Could they really be the murderer?