The daughter of a brilliant but mentally disturbed mathematician, recently deceased, tries to come to grips with her possible inheritance: his insanity.
Complicating matters are one of her father's ex-students, who wants to search through his papers, and her estranged sister, who shows up to help settle his affairs.
"I am not a father yet, but it is definitely a dream of mine, should I be lucky to have that happen," he revealed.
Hear more of his interview with ET in the video below.
Jake Gyllenhaal is currently single and concentrating on his career.
A member of the Gyllenhaal family and the son of director Stephen Gyllenhaal and screenwriter Naomi Foner, Gyllenhaal began acting as a child with a screen debut in City Slickers (1991), followed by roles in A Dangerous Woman (1993) and Homegrown (1998).
His breakthrough performance was as Homer Hickam in October Sky (1999) and he garnered an Independent Spirit Award nomination for Best Male Lead for playing the title character in the indie cult hit Donnie Darko (2001), in which he played a psychologically troubled teenager alongside his older sister, Maggie Gyllenhaal.
WATCH: Jake Gyllenhaal Reveals He Had a Crush on Jennifer Aniston For Years Many claimed that the two looked flirty, but the pics also only showed Gyllenhaal and Mara in the frame.
If you zoom out, however, you'll see a guy in a gray shirt to the right of the , one of Gyllenhaal's most well-known films.