With Microsoft having already paid $50 million as a downpayment on exclusive rights to two downloadable episodes for “Grand Theft Auto IV,” we knew we were set to get another add-on beyond this spring’s well-reviewed “The Lost and Damned.” On Tuesday, GTA developer Rockstar Games let slip a few details about the next chapter, due out this fall, called “The Ballad of Gay Tony.”

Like “The Lost and Damned,” “Gay Tony” has players taking control of someone other than “GTA IV” protagonist Niko Bellic. In lieu of Niko, or “Lost” hero Johnny Klebitz, you’ll be playing as Luis Lopez, an assistant to Liberty City nightclub owner Anthony “Gay Tony” Prince, who appears in a couple of missions in “GTA IV.”

That’s about all we know. “The Ballad of Gay Tony” will cost $20 and be available through download on Xbox Live. Additionally, Rockstar plans to release a $40 disc that contains both “The Lost and Damned” and “The Ballad of Gay Tony.” The disc will be a standalone game, playable without the “GTA IV” game disc.