While Disney chairman Alan Horn remained mostly tight lipped during an interview at the Loyola Marymount School of Film and Television in Los Angeles, he did let it slip that “Star Wars Episode VII” has already begun shooting and has much of its cast.

“We have a lot of them, it’s not completely done yet,” Horn responded when asked about casting, noting it as the most difficult part of putting the highly anticipated film together.

As J.J. Abrams prefers to keep details under wraps for most of his films, Horn declined to reveal any names. Variety, however, learned in February that “Girls” actor Adam Driver is in talks to play the villain. Actors being considered for the lead role include Ed Speleers, John Boyega, Jesse Plemons, Matthew James Thomas and Ray Fisher.

“We’re actually shooting some of it now,” Horn said, despite previous comments that filming would start next month. The chairman could have been referring to getting B-roll and location shots without having the cast on set, but he didn’t divulge any information beyond that.

The script, co-written by Lawrence Kasdan and Abrams after an early draft by “Toy Story 3” scribe Michael Arndt, was also a challenge, according to Horn. On all other details, though, Horn channeled his inner Yoda to advise those awaiting more news: “Patience, you must have.”

“Star Wars: Episode VII” is produced by Abrams, his Bad Robot partner Bryan Burk and Lucasfilm head Kathleen Kennedy. It’s set to hit theaters Dec. 18, 2015.