Rebecca Hall can thank Jessica Chastain's comically busy schedule for the biggest offer she's had yet: the chance to play the female lead in "Iron Man 3."
Variety reports that Hall -- who has previously starred in "The Town" and "Vicky Cristina Barcelona" -- is negotiating with Marvel to join the future blockbuster. She would play a scientist who develops a new and dangerous technology.
"Sorry to say that 'Iron Man 3' isn't going to work out," Chastain wrote on her Facebook page this week. "My schedule is jammed packed and I can't fit anything else in. The press announced my possible attachment far too soon. I know many of you wanted me to be involved, and I'm so sorry to disappoint you. Hopefully there'll be another Marvel film in my future. Shane Black and everyone on the 'IM3' team are really wonderful. I'm very excited to see the film when it comes out."
If Hall's deal works out, she would join an already jam-packed cast that includes Robert Downey Jr., Gwyneth Paltrow, Don Cheadle, Guy Pearce and Ben Kingsley.
"I am in 'Iron Man 3.' It's official," Kingsley told HuffPost Entertainment this week, though who he's playing remains a mystery.
"That's not for public knowledge ... yet."
"Iron Man 3" is due in theaters on May 3, 2013.
RELATED: Watch Clips From "Marvel's The Avengers"
Earlier on HuffPost:
More:Rebecca Hall Iron Man Rebecca Hall Iron Man Scientist Rebecca Hall Iron Man 3 Rebecca Hall Jessica Chastain Rebecca Hall Marvel
HuffPost Entertainment is your one-stop shop for celebrity news, hilarious late-night bits, industry and awards coverage and more — sent right to your inbox six days a week. Learn more