What must it have been like for the Viennese Jews on November 10, 1938, the morning after Kristallnacht? One day earlier, their synagogues stood, their shops were open and their bank accounts existed. Yet in the blink of an eye their status changed from marginalized to subjugated, and they were helpless to change it.

In “12 Years a Slave,” which is based on a true story, we meet Solomon Northup, an African-American violinist in upstate New York who lived an integrated, privileged life with his wife and two children. It was 1841 and the racial cruelty of the antebellum south might as well have been happening on the moon.

Until, that is, the day Northup accepted a job from a pair of white men to play violin in a circus. Lured to Washington, D.C., he was wined, dined (and wined some more) until he passed out in a drunken stupor. He awoke shackled and enslaved.

The remaining two hours of the film shine an unflinching lens on the vile evil and frenzied violence that defined plantation slavery in the 1800’s. It is a challenge to endure and a relief to conclude. Northup spent a dozen years being passed from master to master, and we witness every humiliation, whiplash and sociopathic plantation owner uncomfortably close-up. The pathos is all the more visceral because we know Northup was born into freedom, and that he is worldlier than his custodians. We feel his desperation. Although the film ends on a happy note, we remain unsettled and sad. Where does this subhumanization of one group by another come from?

The time, place and circumstances of “12 Years a Slave” and Kristallnacht are different, but the same wrong was inflicted. In America and in Nazi Germany, white plantation owners and Aryan SS guards gave themselves permission to enslave people and practice ruthless sadism. What is most disturbing about “12 Years a Slave,” however, is not the desensitizing violence; it is the lack of closure, and the dark thoughts and feelings that evokes. Where is the justice? Where is the retribution? Elie Weisel may have been able to offer God his forgiveness for allowing the Holocaust to exist, but for some of us spectators, that just doesn’t settle the score.

Chiwetel Ejiofor stars as Solomon Northup in “12 Years a Slave.”