Gerard Mercator (1512-1594) was born at the dawn of the Age of Discovery, when the world was beginning to be discovered and carved up by navigators, geographers and cartographers. Mercator was the greatest and most ingenious cartographer of them all: it was he who coined the word 'atlas' and solved the riddle of converting the three-dimensional globe into a two-dimensional map while retaining true compass bearings. It is Mercator's Projection that NASA are using today to map Mars. How did Mercator reconcile his religious beliefs with a science that would make Christian maps obsolete? How did a man whose imagination roamed continents endure imprisonment by the Inquisition? Crane brings this great man vividly to life, underlying it with colour illustrations of the maps themselves: maps that brought to a rapt public wonders as remarkable as today's cyber-world.