Borderlands‘ The Zombie Island of Dr. Ned will arrive in just five days now, bringing the first piece of downloadable content to the fastest-selling new intellectual property of the year. But, how much digital goods does $9.99 buy these days? According to the game’s Design Director Paul Helquist, “probably four to six hours” worth. “It’s probably about the size of the Arid Badlands and one or two of the doglegs.”

As for the content the DLC brings, Gearbox’s goal isn’t adding to the 87 bazillion guns. Instead, the focus is on “the new region and the new plotline and that sorta thing,” Helquist says. And new bad guys — “There’s only one, maybe two monsters in the DLC that are basically the same [as the regular game]” — which can be seen in action right here.

The DLC will arrive on both the PS3 and 360 next Tuesday, on November 24. PC users will get it a bit later.