The actress from Crazy Heart, The Dark Night, Donnie Darko and White House Down, 39, plays Candy Merrell in HBO’s The Deuce, premiering Sept. 10. It’s about the rise of the billion-dollar porn industry in New York’s Times Square in the 1970s. What motivates Candy, who is a hooker and single mom? She is a little bit of a loner. She’s trying to survive, and she’s just keeping her head above water. The role required a bit of nudity. The nudity wasn’t scary for me. The real challenge was to explore being a prostitute in relation to sex, art, money and power. Is motherhood your priority these days? The part of me that’s an artist and the part that’s a mother exist simultaneously. [She and her husband, actor Peter Sarsgaard, have two children.] There are times when I have to make work sacrifices and other times when my family has to. You have the big 4-0 coming up. Is it just a number or does it mean something? I see women who are older than me, some of whom have given up and gone to sleep and that’s that. Other women seem so wise and inspiring, and I would like to move toward being like them.