A thrilling journey deep into the heart of language, from a rather unexpected starting point. Keith Kahn-Harris is a man obsessed with something seemingly trivial - the warning message found inside Kinder Surprise eggs: WARNING, read and keep: Toy not suitable for children under 3 years. Small parts might be swallowed or inhaled. On a tiny sheet of paper, this message is translated into dozens of languages - the world boiled down to a multilingual essence. Inspired by this, the author asks: what makes 'a language'? With the help of the international community of language geeks, he shows us what the message looks like in Ancient Sumerian, Zulu, Cornish, Klingon - and many more. Along the way he considers why Hungarian writing looks angry, how to make up your own language, and the meaning of the heavy metal umlaut.