Is immigration a problem or an opportunity? Do we need walls or doors? The answer to both questions is yes. For decades, Canada was an outlier. The country took in more immigrants than other developed countries, with less opposition. Whatever Canada was doing, it seemed to be working. Immigration was of popular with voters and a model for the world. Americans liberals, conservatives, Silicon Valley, and even Donald Trump looked to Canada as a source of immigration inspiration. And, then, in a few short years, it all came undone. In Five Walls and a Door: How Canada got immigration right, and then wrong, Tony Keller explains how a government that once had the secret sauce for immigration forgot the recipe and broke the system. He also shows how Canadian immigration can be rebuilt better than before, once again to the benefit of all Canadians and as a model for the world.