Believe it or not, marriages are a common occurrence in prisons in the US.  The happiest day of your life can include x-rays, strip-searches and bulletproof glass when you're tying the knot behind bars. The documentary follows three of the thousands of prison marriages, the ups and downs, the highs and lows and all that comes with a wedding day in prison. "The old ball and chain" is literally a ball and chain in some cases.