Mehta juxtaposes the phony narratives of populist ideologues with the ordinary heroism of laborers, nannies, and others, from Dubai to Queens, and explains why more people are on the move today than ever before. As civil strife and climate change reshape large parts of the planet, it is little surprise that borders have become so porous. But Mehta also stresses the destructive legacies of colonialism and global inequality on large swaths of the world: When today’s immigrants are asked, “Why are you here?” they can justly respond, “We are here because you were there.” And now that they are here, as Mehta demonstrates, immigrants bring great benefits, enabling countries and communities to flourish.