CBC Docs looks at the making of Sgaaway K’uuna (Edge of the Knife), which premiered this month at the Toronto International Film Festival. Co-directors Gwaai Edenshaw and Helen Haig-Brown produced the first feature film in the language of Haida Gwaii, the islands off the North Coast of British Columbia. (Home to the Haida First Nations, they had been known before 2010 as the Queen Charlotte Islands.) Why is that unusual? Haida currently has about 20 native speakers and is considered an endangered language; some of the film’s actors had to learn the language before they could memorize their lines.