Geology is the science that studies planet Earth, and geologists are the detectives looking for leads that allow the reading and interpretation of the pages of its history. In the cliffs of Zumaia we find the pages of this great book spread along several kilometers of coast line: A magnetic change, a drop in sea level, one of the greatest warming up periods the Planet has gone through, and a mass extinction that wiped out 70% of the species, with the dinosaurs amongst them. Would the human species survive now the changes that have already happened in the past?