In the build-up to the last December’s release of Tron: Legacy, it was abundantly clear that Disney was hoping to kickstart a new franchise after the original Tron laid dormant for almost two solid decades.  Provided that the sequel performed up to par, director Joseph Kosinski seemed likely to return, along with screenwriters Edward Kitsis and Adam Horowitz.  After six months with little to no movement on another adventure in the Grid, Disney has hired a new writer, David DiGilio, to tackle a hypothetical third Tron film.

THR’s Heat Vision reports that Kitsis and Horowitz were unable to return for another round because of their commitment to the new ABC fantasy series Once Upon a Time, which the duo created and will executive produce.  Interestingly, DiGilio, the writer of the 2006 Paul Walker-sled dog film Eight Below and a graduate of Disney’s writers program, also just got involved in a television series of his own creation.  He recently sold a pitch for a postapocalyptic medical drama titled Last H.O.P.E.(Hospital on Planet Earth) to Showtime.

Tron: Legacy, which starred Jeff Bridges, Garrett Hedlund, and Olivia Wilde, grossed $400 million worldwide.  It was also hugely expensive to produce and market, meaning that the profit margin was thin.  As such, Disney has not yet committed to another entry in the series.  Apparently, the decision to go ahead with a David DiGilio-penned sequel will largely depend on the reception to Tron: Uprising, an animated series set to air on Disney XD next year.

That series, commissioned before Tron: Legacy‘s release, bridges the gap between the 1982 original and its 2010 predecessor.  It will feature the voices of Elijah Wood, Mandy Moore, Paul Reubens, and Bruce Boxleitner.  Kitsis and Horowitz are producing.

As for Joseph Kosinski, Disney recently let go of the director’s project Horizons, aka Oblivion, which he is currently developing it at Universal.  Tom Cruise set to star in the science fiction epic, with production scheduled to begin this Fall.  It’s unknown whether that means he would be unable to return to Tron, should a sequel actually come to pass.