Shape Dynamics is a new theory of gravity based on fewer and arguably more fundamental principles than the general theory of relativity. It reproduces all of the hitherto confirmed predictions of Einstein's theory but is much more restrictive in the solutions that it allows. Besides being therefore a more strongly predictive theory, it also reveals new aspects of gravity that have the potential to transform our understanding of the Big Bang and black holes. Flavio Mercati has been actively involved with the recent exciting developments of Shape Dynamics. His monograph includes a valuable account of the historical background to the theory and its conceptual underpinnings. It is an excellent introduction suitable for readers of a wide range of abilities: from physics and mathematics undergraduates, to active gravitational and cosmological researchers. Julian Barbour, author of The Discovery of Dynamics and The End of Time sakriti opis