A moose walks into a rural Maine town called Oslo. Pierre Roy, a brilliant twelve-year-old, loses his memory in an accident. Three families are changed for worse and better as they grapple with trauma, marriage, ambition, and their fraught relationship with the natural world. Oslo, Maine inspects the strengths and limitations of seven average yet extraordinary people as they reckon with their considerable collective failure around Pierre's accident. Alliances unravel. Long held secrets are exposed. And throughout, the ever-present moose is the linchpin that drives this richly drawn story, filled with heartbreak and hope, to its unexpected conclusion.