Devoted fans of the Dresden Files, one of the fastest-growing urban fantasy series, should plan to stay up late April 6 for a party to celebrate the release of "Turn Coat," author Jim Butcher's latest novel about professional wizard Harry Dresden.

Like the Harry Potter parties that heralded the advent of a new adventure, the Dresden Files celebrations -- for adults -- involve dressing up in costumes, a pre-signing and, 30 minutes before midnight and the book's release, a reading by the author.

For those who haven't met Harry Dresden yet, Butcher describes him as "Dirty Harry Potter," and when "Sam Spade meets Gandalf" -- he's a tough private eye-like character with magical abilities.

Set in Chicago, the book chronicles Harry's latest dilemma, clearing the name of Morgan, formerly his chief persecutor and now accused of treason against the White Council. Beset in his task by supernatural bounty hunters and, as the title indicates, a turncoat, Harry has to clear Morgan's good name and make sure no one loses his head, including his own.

Butcher, who lives in Missouri and who originally set his book in Kansas City until his writing teacher convinced him to move Harry to Chicago, says he created his hero to be a blue-collar type of guy rather like Bruce Willis' character in the "Die Hard" film series.

A lover of fantasy since he was a child and who devoured books by C.S. Lewis, Lloyd Alexander and J.R.R. Tolkien, Butcher despaired when he couldn't find books he wanted to read.

"So I decided to write one instead," says Butcher who is just finishing the sixth novel in his Codera Alexa series, which are classified as epic classic fantasies and, like the Dresden Files, frequently make the New York Times and USA Today best-seller lists.

Though the Codera Alexa series is ending with the sixth installment, Dresden fans shouldn't despair. Butcher says there are about 20 more Dresdens to come.

FYI: "Turn Coat" by Jim Butcher