Boarded the train there's no getting off. (9)
This line helps to continue the world of the poem even after we've stopped reading. Presumably, this train is headed somewhere, but we're left to wonder where it's going. Also, this line demonstrates the difference between the metaphorical poem, where an actual train is chugging along, and the story behind the metaphors, where a woman is unable to change the direction her life is going in.