This book is the first step of a spiral journey into the world of the immensely small, into the universe that palpitates in a drop of water. These images are so seductive they seem pure imagination. Through them we come into contact with some secret and essential guests of the living universe. Without their presence in the chain formed by all living creatures, the processes of life as we know it would be just a chimera. But these images also reveal the inner beauty of the world. On these pages, the wise old claim that the cosmos can be seen in a drop of water reveals how true it is with such beautiful, hypnotic and exact precision. We just need to open our eyes to appreciate all the beauty that had hitherto remained hidden.