Mary Elizabeth Winstead has been working steadily in film and on television since 1999, when at age 14 she got her first regular gig, on the fantastical NBC soap opera “Passions.” She thought she was signing on for “a daytime version of ‘Dawson’s Creek,’” Winstead says, but then the show’s campily supernatural heart revealed itself. “Every day was just sort of, like, what is happening? It was very strange!”