Gr 10 Up-Marco Sanchis hopes to become a great detective like his father, and he has even set up his own detective agency with his steprother Klaus and stepsister Mireia. When his best friendand the girl he secretly lovesAlba comes to Marco for help in finding the person who has been sending her obscene messages through Whatsapp, Marco wastes no time in discovering and humiliating Alba's boyfriend, Xavi. Thinking this will win him points with Alba, Marco is surprised to find Alba is deeply upset with him. Even worse, Alba faints and falls ill at school, and Marco soon finds out that if Alba's biological parents are not found, she may die from leukemia. While juggling the insults of Profesora Sanmartin and simultaneously trying to find who is stealing exams, Marco races against time to try to save the girl he knows still has a life left to live. Along the way, Marco learns a few lessons from his dad about life and about being a detective. With cultural references to Booktubers and music and a tone that switches between comedic and grave, this short novella is sure to be a fast and engaging read for teens. VERDICT Recommended for libraries with a Spanish-language collection for young adults. Selenia Paz, Harris County Public Library, Houston, TX