Canadian actress and filmmaker Sarah Polley investigates certain secrets related to her mother, interviewing a group of family members and friends whose reliability varies depending of their implication in the events, which are remembered in different ways; so a trail of questions remains to be answered, because memory is always changing and the discovery of truth often depends on who is telling the tale.

Canada was led to war by a bigoted, ignorant, self-obsessed Minister of Militia, who may well have been clinically insane, but the importance of Canada's contribution in that war owes a great deal to him. The man of course, was Colonel - later made Lieutenant General by his own hand - Sam Hughes. Sam's Army is a compelling portrait of a complex man and the formidable military he built. Sam Hughes was not your standard-issue military leader. Canada's World War I Minister of Militia and Defence concentrated power in his own hands, insisted that the Canadian military use the ill-conceived Ross rifle and liberally promoted his cronies. But there was no denying Hughes was a visionary. He assembled the world's largest-ever volunteer army and bucked superiors to keep his ferocious fighting force together in one Canadian Corps.