On a cold night in February, 1884, just metres north of the border on Sumas Prairie, BC, an Indigenous boy named Louie Sam was lynched by a mob of mounted vigilantes. The vigilantes had ridden up from Nooksack Valley in Washington Territory, hell-bent on avenging the murder of one of their neighbours, which they had pinned on Sam. The American origin of the mob, and the fact that Sam's murder was one of only two recorded lynchings in Canadian history, have led historians and writers to represent it as an isolated and foreign incident—disconnected from people and events north of the border and an aberration from the norm of Canadian history.

When placed within the historical context of that time and place, the vigilante murder of Sam no longer appears to be an isolated and foreign incident. Rather, it emerges as the result of a series of events and causes on both sides of the border, with the active participation of locals in both BC and Washington Territory. Deadly Neighbours takes a closer look at the lynching, and in so doing reveals a more complex and disturbing chronicle of the deadly grip the leading White settlers in Nooksack and Sumas held over the area—and most notably, over their Indigenous neighbours.