It seems inconceivable – a Kafkaesque nightmare come to life.

Here in utopian, civil rights-upholding Canada, five men have spent a total of over 50 years in prison or under house arrest, even though none has ever been charged with a crime. The men – Muslims all, natch – were each arrested between 1999 and 2003 under a so-called security certificate, a blunt instrument of immigration law that enables the federal government to detain non-citizens it suspects of being potential dangers to national security. But because the evidence is kept secret, to protect sources, detainees can never clear their names.

First-time director Amar Wala gave himself a corker of an assignment with this case, a messy stew of constitutional law and the personal dramas of four men and their families, which unfold over more than a dozen years. So if the filmmaking is bumpy – tonal shifts, jarring cuts between interviews conducted years apart, and herky-jerky individual narratives that reach different conclusions – its quiet moral outrage never wavers.

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Wala gives the final word to the son of one of the men, who was a mere child when his father was first arrested. "Our strength is in our humanity, our justice system, and who we are as a people," he says, displaying impressive, improbable hope. "If you let fear dictate how you live your life, then you lose everything."