Louisa and Tom are growing up in their father's Utilitarian educational system
From the very beginning, we can see how crazy the no-emotions no-morality system their father has been using to educate them is. The question at this point is just how messed up are these two?
Tom is hired as Bounderby's bank clerk, Louisa marries Bounderby
Their ties to Bounderby and their hatred of him set up everything that will follow. Tom hates his job, starts gambling, and steals from Bounderby's bank. Louisa hates her husband, and starts paying attention to Harthouse.
Louisa falls for Harthouse, Tom frames Stephen Blackpool for bank robbery
Tom and Louisa both meet a person around whom a crime/potential crime will happen. However, in both cases, the idea initially is to interact with this person in some positive manner. With Harthouse, Louisa finally has someone to talk to about Tom and who promises to help set him straight With Stephen Blackpool, Tom has an opportunity to help a man who is much less fortunate.
Louisa collapses at her father's house after confronting him about the way she and Tom were raised; the bank robbery is discovered and Stephen disappears
The crimes have been committed. Well, OK, the Victorians were kind of squeamish about the sex outside of marriage, so that crime is almost committed. Instead, Louisa has a drawn out rant at her father and his crazy theories. But the bank is definitely actually robbed.
The search for Stephen intensifies
Stephen is the one man who can provide some evidence against Tom. When he leaves town and can't be found, suspicion for the bank robbery falls on him. If he can't be found, Tom will get away with his crime.
Louisa and Bounderby permanently separate; Stephen dies and Tom escapes from justice
Louisa and Bounderby end up living apart, probably for the best, since she hates him and he looks down on her. Stephen is found half-dead and does testify against Tom. The Gradgrinds band together to help Tom escape rather than face justice. Tom ends up living in exile.
The bad are punished and the good rewarded; Louisa, Tom, and Gradgrind, learn from and make peace with their mistakes
Mostly the conclusion seems to be that everyone who has at all been contaminated by the Utilitarianists shouldn't reproduce (a.k.a. have children). Also, the reader should be totally energized to go out into the world and make some change! (See our "What's Up With the Ending?" section for more details.)