Basically, it's a story of a person trying to do good but then he slips up. And then comes a friend who says he can help Mario. That's Pablo. His life is better than Mario. Mario is his partner in crime. He spews a lot about earning next to nothing on a decent job when Mario can go back to their old shady ways and can earn a lot. Gloria, however, isn't like that. It's like she'd rather be poor than rich because of dirty ways and dishonest money. Gloria was the one who turned Mario into someone good. And here comes the friend who wants him to be bad again, offering money for their sick child. And Mario? He didn't really have a choice. He gave up on the good life and he goes with Pablo. He promises to be safe for Gloria. The play ends with Gloria crying and Tita cries with her.
The whole play is sort of a morality thing. When one is trying to change for the better, here comes temptation and he give into it for his own reasons. He gives up on trying to be better because he thinks that he cannot do it and that he isn't suited to live that kind of life. He ignores the pleas of his wife to try