Today, there are more borders in the world than ever before in human history. Crawford travels to borders old and new. He follows the story of borders into our fragile and uncertain future - towards the virtual frontiers of the internet and the shifting geography of a world beset by climate change. Blending history, travel and reportage, this is a wideranging journey through the history of borders and an examination of their role in shaping our world today. For readers of Peter Frankopan and Tim Marshall.