Joss Whedon, the creator of "Buffy the Vampire Slayer," said he’s working on another installment of an Internet-based miniseries, reports Yahoo’s MovieTalk.

The series is "Dr. Horrible’s Sing-a-Long Blog," starring Neil Patrick Harris, the story reports.

"We have been working on that for a while," Whedon said, according to the story. "It’s been hard, because we all have jobs, and some of them are extremely taxing. But we have had a vision of the thing for a while, we have been working on it, we have a bunch of songs and a few scenes. We need a little free time, and right now that’s plenty hard to come by."