The literature on migration in political philosophy is by now mature, and well-trodden argumentative paths map the contours of its central questions. This makes it all the more impressive that Michael Blake's Justice, Migration, and Mercy manages to navigate those questions in a novel and genuinely distinctive way, as well as to chart out new routes for exploration in the terrain of debate. It will prove valuable to both students of migration in political philosophy, for the lucidity with which it approaches its central questions and relates them to contemporary migration politics (especially in the USA), and to partisans in the debates in which Blake engages, for the original perspective that it articulates and for Blake's thoughtful engagement with his interlocuters.