"12 Years a Slave" is based on the real Solomon Northrup's account of that period, published in 1853. I expected it to be emotionally harrowing to watch, but found it strangely unaffecting much of the time. In Hollywood hands, the memoir may have been massaged into a standard three act storyline, with character arcs and dramatic highs and lows accentuated to create a heart-tugging cinema experience. However here Palme D'Or winner McQueen's art house sensibility and British observer status is married with Brad Pitt's /Plan B Productions's social justice orientation. The result is more akin to a dramatized biography, with the camera bearing witness and leaving viewers to respond as we will.