In January of 1947 the body of a woman, later identified as Elizabeth Short, was found mutilated and abandoned in a vacant lot Los Angeles. In the papers (ever eager to run with a story of this ilk), she became known as "the Black Dahlia" after a film of the same name.
In June of 1958 the assault and murder of another woman, Jean Hilliker (formerly Ellroy), hit the L.A. papers. Unfortunately, there were probably many other victims who came in between them, but these would be the two murders that most impacted the life of the young James Ellroy (still known then as Lee Earle Ellroy).
As described in the afterword to this 2006 edition of his book (which accompanied the release of its movie adaptation), the fictionalized story is inspired by the lives and deaths of both women. In real life, both murders remain unsolved.
James Ellroy's world is a dark, dark place, one that is corrupt in every sense of the word. The detective (and ersatz Ellroy), Dwight "Bucky" Bleichert, though by no means naïve at the start, comes to see how the most gruesome elements can seep into and pervade every aspect of one's life. Innocence isn't lost, it was never there to begin with.
The writing is frantic and maniacal at times – intentionally so. The characters' frustrations become your own. I found myself putting the book down and picking it back up in a huff, too haunted to just leave it alone. I certainly could not live on a literary diet James Ellroy alone (though I imagine that doing so would result in actual weight loss), but he is an undeniably powerful writer whose words (like the Dahlia's smile) will never really leave you alone.