A traveler visits a friend and tells him about the encounter with a mysterious woman he falls in love with. At one point, she disappears without a trace.
It is now Zarco who tells Felipe the encounter with another mysterious woman a few years ago and who has not forgotten, and who also disappeared without warning. They wonder if she wouldn't be the same.
Felipe meets again the woman he fell in love with and suddenly disappeared, but she rejects him and says it is the last time they will meet. Zarco continues to investigate the crime of the skull.
Finally Zarco meets again with the mysterious woman of the past, which promises him eternal love. When speaking with Felipe they agree that it is the same that both knew. But solving the crime of the skull with the nail will bring despair.