Rick McCallum, producer of the Star Wars prequels, recently revealed the staggering cost behind the cancelled Star Wars: Underworld series: a jaw-dropping $40 million per episode. This exorbitant price tag, driven by the ambitious scale of each episode surpassing even the feature films, ultimately sealed its fate. "The problem was that each episode was bigger than the films," McCallum explained on the Young Indy Chronicles podcast, adding that the project's failure remains "one of the great disappointments of our lives."

With 60 third-draft scripts penned by "the most wonderful writers in the world," showcasing a "sexy, violent, dark, challenging, complicated, and wonderful" side of the Star Wars universe, the budget proved insurmountable. Even at the early 2000s, the potential cost—easily exceeding $1 billion—was beyond reach, even for George Lucas. McCallum noted that the series' ambition would have fundamentally reshaped the Star Wars universe, likely preventing Disney's subsequent acquisition of the franchise. Disney's acquisition of Lucasfilm and Lucas's departure ultimately marked the series' demise.

While McCallum remained tight-lipped on plot specifics, fan speculation centers on bridging the gap between Revenge of the Sith and A New Hope. He previously hinted at an entirely new cast, significant expansion of the Star Wars universe, and a mature audience target, departing from the typical teen and child demographic.

First unveiled at Star Wars Celebration in 2005, and with test footage surfacing in 2020, Star Wars: Underworld remains a tantalizing "what if?" Sadly, it seems unlikely we'll ever see this ambitious project come to fruition.