The Footprint ― The brilliant work of the artist and, specifically, the realism with which Luzón brings this story to life forces us to experience the protagonist's emotions in every stroke.  “Throughout the book, a striking contrast emerges an animal world with human feelings.”
The compositions and techniques with which the artist plays to recreate the various scenarios and breathe life into the protagonist’s emotions overwhelm the reader to the point where it is impossible not to empathize with him. Images and verses that envelop us in an atmosphere as turbulent as friendship can be a difficult beginning, with an initial rejection of the different, what we call “strange,” which quickly finds that gift of life called friendship, the one that allows us to face and even forget all the adversities that cross our path. 

A strong and intense friendship that carries us along on a river of fun and well-being and that both Sobrino and Luzón manage to make us feel between the pages of this beautiful album.
Companionship can be one of the most beautiful experiences to be discovered in childhood, but it can also be one of the most painful when it breaks down. That’s why this story isn’t just about how good it is to have a great friend. Sometimes things go wrong; paths diverge, and, without expecting it, lives that were once one become separated forever. 
Dealing with the grief you experience, especially for a child, is not easy.
This is why this beautiful book gives us a powerful message of hope and illusion:
“That those who were here may have left an indelible mark, but they also leave a space that can be filled by others who are ready to make us immensely happy.”. 
Because in childhood, during emotional turmoil, friendship can be a wonderful experience or the most significant lesson.