It's always nice when a pleasant surprise pops up in your inbox late in the afternoon. That was the case with an invite that came out of the blue for a screening next Thursday (July 10) at CAA of Joss Whedon's latest concoction, the made-for-Internet "Dr. Horrible's Sing-Along Blog."

It's a three-parter with name-brand stars, Neil Patrick Harris, Nathan Fillion, Felicia Day and the fabulous Simon Helberg from my new favorite show, "The Big Bang Theory." "Dr. Horrible" seems to be something of a Whedon family hootenanny. It's penned by Joss, his brothers Jed and Zack, and Jed's fiance, Maurissa Tancharoen. Jed and Maurissa are writing partners working for Joss on his day job, the upcoming Fox drama "Dollhouse."

Zack, as readers of On the Air already know, is a comer who is not only endowed with screenwriting in his DNA (his father and grandfather were also in the family biz) but was taken under wing a few years ago by none other than David Milch. Zack (pictured right) worked with Milch on "Deadwood" and "John from Cincinnati," and even wrote "John's" big-wave-wild finale (I'm not ashamed to say that I really enjoyed that show).

In his spare time during the past few months, Zack's been busy working on "Dr. Horrible" and writing a comic book, "Captain Hammer," based on a character from "Dr. Horrible." You can check out his comicbook wordsmithing right here.

"Dr. Horrible," which Joss also helmed, is set to be unleashed on the Web over three days -- July 15, July 17 and July 19. If there's some numerology significance to those dates, maybe we'll find out about it at the screening.

On the "Dr. Horrible" website, Joss explains his reasoning (as only he can) for tackling this project.