"Zero Is The Key" by Robert J. Guerrera is good honest clean fun - and my daughter loved it! It's one of those books the make you learn while having fun :) Robert's strengths as an author are multi-fold, but the two that stood out to me are his ability to build and sustain an exciting, non-stop plot and his meticulous detail in creating multi-faceted characters. Declan and Dalya were life-like on the page as they struggled with danger, their surroundings and with each other. The two teens, who are great role models for young readers, are the real fuel for this story. The overall story is well written and you will be glad that you picked it up!