Luisa Laurent (Silvia Abascal), a property tax expert on vacation, receives a call from her boss Eduardo, asking her to rush to the Valdemar Mansion in Monte Negro. The mansion was built in the Victorian era and has a long history. A month ago, Eduardo sent his subordinate Orcia to conduct an asset appraisal and prepare to auction the mansion. However, Orcia has not been heard from since then. As the auction date is advanced, he has to find Luisa in a hurry. After some bargaining, Luisa is ordered to take charge. She came to the dilapidated mansion, but when she inspected the interior, she saw a highly decomposed body. Four days later, Luisa also disappeared. Her boss Maximilien (Eusebio Poncela) was helpless and found private detective Nicolas (Óscar Jaenada) to investigate the whereabouts of two employees. However, during the investigation, Nicolas slowly uncovered the heart-wrenching and little-known past of the Valdemar Mansion...