Alexander Vilenkin’s recent book is a wonderful popular introduction to contempo­rary cosmology. It contains provocative discussions of both the beginning of the universe and of the fine-tuning of the universe for intelligent life. Vilenkin is a prominent exponent of the multiverse hypothesis, which features in the book’s title. His defense of this hypothesis depends in a crucial and interesting way on conflating time and space. His claim that his theory of the quantum creation of the universe explains the origin of the universe from nothing trades on a misunderstanding of “nothing.”