Twenty years ago, a raw and impressionable Detective Michael Green helped convict a young professor for the murder of an attractive co-ed. From behind bars, the man continued to hound Green with letters protesting his innocence. Shortly after being paroled, he is found dead. Is it suicide? Revenge?

When Green receives one last letter, posted before the man's death, in which he plans to track down the real killer, Green realizes he may have made the biggest mistake of his career — a mistake which cost an innocent man his liberty and ultimately his life. To determine the truth, Green is forced to re-examine old evidence and stir up old wounds to stare down a far greater evil hiding in plain sight.