Is The Crystal Cuckoo based on a true story?

Netflix’s The Crystal Cuckoo, a Spanish thriller drama series, premiered its first episode on the streaming platform on November 14, 2025. The series is directed by Juan Miguel del Castillo and Laura Alvea.

The Crystal Cuckoo ​​​​​​is not based on a true story. The series is adapted from the fictional novel El Cuco de Cristal, written by Javier Castillo.

The novel was adapted and written for the screen by Jesus Mesas and Andres Roig. While the entire storyline and plot arcs of the series are fictional, it is completely adapted from the story of the novel.

The show is based on the life of a young girl called Clara Merlo, who ends up receiving a heart transplant that saves her life. To ensure that she pays her due respects to the person who donated her heart, she travels to a remote village to track down the young man and his entire family.

The plot of the show picks up its pace once she realizes in the village that there have been numerous mysterious and suspicious disappearances of the village folk, and all of them are somehow tied to the members of the young man's family, who have all been grieving his passing.

Clara becomes entangled in the town's secrets, which seem to beckon to her and finds herself caught in a deadly trap.

Details explored on the adaptation and storyline of Netflix’s The Crystal Cuckoo

The novel from which this series is adapted has been published in 63 countries worldwide.

The series boasts a stellar cast, featuring veteran actors and actresses. Catalina Sopelana plays the role of the protagonist, Clara Merlo, Alex Garcia plays Miguel and Tomas del Estal plays the character of Gabriel. 

The Crystal Cuckoo is set in a small, fictional remote village called Yesques, located just outside Madrid, Spain. The storyline revolves around a 25-year-old doctor called Clara Merlo, who ends up suffering from a fatal heart attack while working her medical residency job in Madrid.

However, miraculously, she ends up receiving an organ donation that saves her and gives her a second chance at life. Once she recovers, she ends up being overcome with an overwhelming urge to find out who her donor was, but finds it difficult to track the person since in Spain, it is illegal to reveal donor details.

Clara ends up spending a lot of time on the internet to try to find out who it was, and finally unearths that it was a man called Carlos Ferrer who had been suffering from brittle bone disease for a long time and had tragically died in a car accident. 

Clara calls Carlos’s mother, Marta, and ends up visiting the village where she and Carlos's other family members live.

Once she goes over there, she finds out how Carlos’s father, Miguel, had disappeared suspiciously in 2005, and it was very similar to other unsolved cases, dating back more than 20 years. Throughout the series, Clara collaborates with Juan, a police officer, as they attempt to solve the mysteries of the small town.

Stay tuned for more updates.