Numbers have fascinated people for centuries. They are familiar to everyone, forming a central pillar of our understanding of the world, yet the number system was not presented to us "gift-wrapped" but, rather, was developed over millennia. Today, despite all this development, it remains true that a child may ask a question about numbers that no one can answer. Many unsolved problems surrounding number matters appear as quirky oddities of little account while others are holding up fundamental progress in mainstream mathematics. Peter Higgins distills centuries of work into one delightful narrative that celebrates the mystery of numbers and explains how different kinds of numbers arose and why they are useful. Full of historical snippets and interesting examples, the book ranges from simple number puzzles and magic tricks, to showing how ideas about numbers relate to real-world problems, such as: How are our bank account details kept secure when shopping over the internet? What are the chances of winning at Russian roulette; or of being dealt a flush in a poker hand? This fascinating book will inspire and entertain readers across a range of abilities. Easy material is blended with more challenging ideas about infinity and complex numbers, and a final chapter "For Connoisseurs" works through some of the particular claims and examples in the book in mathematical language for those who appreciate a complete explanation. As our understanding of numbers continues to evolve, this book invites us to rediscover the mystery and beauty of numbers and reminds us that the story of numbers is a tale with a long way to run...