Director Carlos Bolado appear in one scene of the film as a homage of "Bajo California: The Limit of time" who directed in 1998.
The main character's name "Juan" was named in honor of documentary filmmaker Juan Carlos Rulfo, who co-distributed the documentary En el hoyo (2006) with Octavio Maya.
During the creation of the screenplay, Octavio Maya was looking for a round pendant to give the idea of cyclic, a message that is present all along the story. As result of that research, one night Maya dreamed he was in the house of the famous Greek translator Cayetano Cantu, along with the Nobel prize writers Carlos Fuentes and Octavio Paz, who suggest him that the round piece would be like "the ring" of the movie "The Lord of the Rings."
The ring held by the character of "Juan" (Rodrigo Murray) was a unique handmade ring of two pieces, both containing the encrypted symbols of the four elements of earth in Mayan symbolism.
For the first time Adrian Alonso plays two roles in the same film. On one side he plays one of the bullies that cause the accident in the pool (Flashback of Juan). At the same time he appears as one of the Indian kids who pushes through the character of Juan. This is also the first film that Adrian Alonso plays a "bad boy".