UKLO (the United Kingdom Linguistics Olympiad) is a voluntary organisation which brings the fun of detective puzzle solving to UK schools using the theme of languages. We create mysterious puzzles written in an exotic language that students cannot read, and the task is to work out what it means with hints and clues. We offer the competition at four levels of difficulty for KS2 – KS5, and provide Gold, Silver and Bronze awards, as well as participation certificates, at each level. The highest scoring students proceed through a couple more rounds of testing and coaching before we present them for the International Linguistics Olympiad (IOL) where they compete against other countries. Our problems require general thinking skills rather than prior knowledge either of the language concerned or of linguistics.