The Great God Brown is a play by Eugene O'Neill, first staged in 1926.
After the two men inherit the business, Dion retires to paint, but fails and eventually dies.
Brown is accused of killing his "real" self, and only the unmasked prostitute Cybel is there to comfort him.
Eventually Billy dies as well, and years later Margaret pledges her undying love to Dion's mask.
Act two, scene four of Cummings' play showcases two masked characters, Will and Bill, who exchange identities.