Rings Upon the Water — Mike Delany

In Volume 1 of the Fergus O'Neill series, "Gus" as he is known to his friends, sets out to build a cabin on Moose Jaw Creek in the Alaska bush. The native Alaskans have a saying that 'a white man too long alone out there will go mad'. His encounters with a mysterious woman, a bear that would not die, and two brutal brothers who raped and killed with impunity, made Gus think perhaps he had gone a little crazy. It takes his two closest friends, a retired State Trooper and a bush pilot/veterinarian to help him discover the strange truth.