From the top of the world, Hudson Bay looks like an enormous paw print on the torso of the continent, and through a vast network of lakes and rivers, the water in this bay connects to oceans across the globe. Here, at the heart of everything, walks Nanurjuk, or Nanu, one polar bear among the six thousand that traverse the 1.23 million square kilometres of ice and snow covering the bay. For millennia, Nanu's ancestors have roamed this great expanse, living, evolving, and surviving alongside humans in one of the most challenging and unforgiving habitats on earth. But that world is changing. In the Arctic's lands and waters, oil has been extracted and spilled. As global temperatures have risen, the sea ice that Nanu and her young need to hunt seal and fish has melted, forcing them to wait on land where the delicate balance between them and their two-legged neighbours has now shifted. This is the icescape that author and geographer James Raffan invites us to inhabit in Ice Walker. In precise and provocative prose, he brings readers inside Nanu's world as she treks uncertainly around the heart of Hudson Bay, searching for nourishment for the children that grow inside her. She stops at nothing to protect her cubs from the dangers she can see,other bears, wolves, whales, humans and those she cannot. By focusing his lens on this bear family, Raffan closes the gap between humans and bears, showing us how, like the water of the Hudson Bay, our existence and our future is tied to Nanu's, and asks us to consider what might be done about this fragile world before it is gone for good. Masterful, vivid, and haunting, Ice Walker is an utterly unique piece of creative non-fiction and a deeply affecting call to action.