In 1925, she adapted
The Plastic Age by Percy Marks and sold it to
Preferred Pictures for $40,000. Clara Bow starred in it. Afterwords she signed up with MGM and worked with stars like Greta Garbo, John Gilbert, Emil Jannings and Barbara Kent. She was good friends with actress Norma Shearer although their relationship soured after Maas advised Shearer against marrying producer Irving Thalberg, whom Maas felt was a "mama's boy".
Between 1938 and 1950, Maas and her husband wrote screenplay after screenplay. Almost all were "swell fish", a term for scripts that never see the light of day. In 1947, Maas wrote her final screenplay,
The Shocking Miss Pilgrim, a story about feminism in the late 19th century.
I know I've been hard on the motion picture industry [in the book] ... [T]he facts and the stories I tell -- about the plagiarism and the way I was handled and the way other writers were handled -- are true. If anybody wants to take offense at the fact that I tell the truth and I'm writing this book ... [I] can get my payback now. I'm alive and thriving and, well, you SOBs are all below, because I've lived to 99. And I quit the business at 50.