While it is responsible for today's abundance of flat screens - on televisions, computers, and mobile devices - most of us have only heard of it in the ubiquitous acronym, LCD, with little thought as to exactly what it is: liquid crystal. In this book, Esther Leslie enlightens us, offering an accessible and fascinating look at - not a substance, not a technology - but a wholly different phase of matter. As she explains, liquid crystal is a curious material phase that organizes a substance's molecules in a crystalline form yet allows them to move fluidly like water. Observed since the nineteenth century, this phase has been a deep curiosity to science and, in more recent times, the key to a new era of media technology.