Starting with a simple question, 'what do street addresses do?', Deirdre Mask travels the world and back in time to work out how we describe where we live and what that says about us. From the chronological numbers of Tokyo to the naming of Bobby Sands Street in Iran, she explores how our address - or lack of one - expresses our politics, culture and technology. It affects our health and wealth, and it can even affect the working of our brains. From ancient Rome to Kolkata today, from cholera epidemics to tax hungry monarchs, Mask discovers the different ways street names are created, celebrated, and in some cases, banned.