The Western Arctic's mammoth Mackenzie Delta is the second largest in North America after the Mississippi. It is a biological "hotspot", a transition zone between ecosystems - from the familiar boreal forest, across the tree line to the ever-frozen tundra. Here we find strange and mysterious landforms above an immense underbelly of permafrost featuring a phenomenal diversity of microorganisms, and strange creatures that tell a story of an ever changing Arctic. This is the migratory destination - and summer home - to several million birds, fish, animals...and humans.