In the industrial city of Coketown, Josiah Bounderby is a rich and fairly obnoxious factory owner and banker. He loves to tell everyone he meets about how he grew up in the gutter, abused by a drunken grandmother. He is friends with Thomas Gradgrind, a rich politician and an education reformer in whose school students only learn about facts. Gradgrind's own children, Tom and Louisa, also grow up in this system. The kids are forbidden to be creative or imaginative or to have too many feelings. Gradgrind is basically trying to make kids into robots, with predictably bad results.
When a traveling circus show comes to Coketown, one of the clowns abandons his daughter, Sissy Jupe, there. Gradgrind takes her in as a servant. She is a natural, happy, not particularly robotic girl, and his system does not seem to make too much of a dent in her good nature.
Louisa and Tom grow up (well, not really – she is nineteen and he is seventeen, but everything happened faster back in the day, especially for robot-children). Gradgrind basically gives both of them to Bounderby. Tom works for him as a bank clerk, and poor Louisa ends up marrying the guy. Oh, did we mention that he's a nasty and annoying? And that Louisa is grossed out by the sight of him? And that he has been really creepily waiting to marry her? Let's all say it together now – ewwwww. But, obviously Gradgrind thinks everything is fine – because since when do robots care about that kind of thing?
Meanwhile, in Bounderby's factory, a worker named Stephen Blackpool is the world's most decent man and he leads a pretty sad life. He got married too young to a woman who is now a raging, half-crazy alcoholic. He pays her to stay away from him, which she mostly does, except when she doesn't. He is also in love with a factory worker named Rachael, but they're both out of luck, obviously. We know what you're thinking (Stephen should get a divorce), but that's not the way Victorian England rolled. As Stephen finds out from Bounderby, to get a divorce he would need to pay for Parliament to pass a law letting him do it. Then he'd have to pay for another law allowing him to remarry. Not happening.
A year later, Louisa is still pretty miserably married to gross Bounderby. Tom, meanwhile, is getting into his own trouble with being a lazy bank clerk, gambling, staying out till all hours, and generally behaving like a jerk to his sister. Bounderby is as unpleasant as ever, and Gradgrind has now been elected to Parliament. The four of them meet James Harthouse, a smooth operator who claims to be trying to get into politics. He mostly just coasts on his good looks, his wealth, and his attitude of completely not caring about anything or anyone. Because he is a born gentleman, he is instantly the coolest, most popular kid on the block. He decides to use that popularity to seduce Louisa. Hmm, let's see, Louisa's husband revolts her, she has never been taught about emotions or how they work, and Harthouse is hot! But on the other hand, adultery is a really big no-no…. Stay tuned to see what happens!
In the factory, all the workers are being organized into a union. Everyone is psyched to finally stick it to the man, except Stephen, who for some undisclosed personal reason doesn't want any part of it. So, the other workers decide to ignore and ostracize him. Then Bounderby asks Stephen to rat on the union. When he refuses, Bounderby fires him. Stephen is forced to look for work elsewhere. Before he leaves, Louisa gives him some traveling money, and Tom in secret asks him to loiter in front of Bounderby's bank for a few nights. To which the obvious answer seems "Um, no thanks," but Stephen agrees.
The morning after Stephen leaves, Bounderby discovers that the bank has been robbed! Of only 150 pounds. But still, a crime. Suspicion naturally falls on Stephen, who seemingly was casing the joint before he left. People also suspect an old woman who periodically comes in to town to watch the bank for unknown reasons. Bounderby leaves town to personally oversee the investigation.
Seizing the opportunity, Harthouse reveals to Louisa his passion for her and asks her to run away with him. She seems to agree to a complicated plan involving meeting him later, but instead takes the train to her father's house in Coketown. For the first time in her life, she confronts Gradgrind about the unnaturalness of her upbringing. She tells him she might be in love with Harthouse, confesses that she almost had an affair, and then faints. Gradgrind is shocked, and he finally realizes how much he messed up his kids.
Trying to keep things civil, Gradgrind asks Bounderby to let Louisa be a semi-permanent "visitor" at her father's house. But Bounderby is all like, "Actually, no, because you pretty much sold her to me, remember? If she doesn't come back by tomorrow, this marriage is over." This might seem ideal. But it means that Louisa would no longer be financially supported by Bounderby, but would still have to be married to him legally. She'd be totally stuck. Sissy seeks out Harthouse , telling him to leave and never come back.
At the same time, Sissy Jupe and Rachael are worried about Stephen and try to find him. Taking a walk across the countryside they stumble on him (literally) lying almost dead in a huge well dug by some factory owner and not marked in any way. He is fished out, pleads his innocence about the robbery, and dies. Yes, sorry, no happy ending for the only decent guy in the whole book. Tom flees, and Louisa and Gradgrind realize that he is the bank robber, and that the only hope is to smuggle him out of the country. Tom hides as a clown in the same circus where Sissy's father used to work. When Gradgrind confronts him, Tom tells his father that political economy made him into a thief, and if he hadn't stolen the money, someone else would have.
Just as Gradgrind is about to put him aboard ship, the family is discovered by one of Gradgrind's old students, Bitzer. Bitzer is quite the economist and refuses to be swayed by Gradgrind's begging to let them go. After all, Bitzer has learned only to advance his own self-interest, which at this point indicates that he should capture Tom to get the probable reward. This is the final nail in the coffin of Gradgrind's educational theory. Still, the circus guys help Tom get away.
In the end, Bounderby dies of some kind of fit in the street. Gradgrind lives to old age and tries to undo the damage he did to his children. Louisa remains unmarried and childless (which is a pretty severe punishment back in those days). Tom eventually feels bad about being so awful, but has to remain abroad. Rachael lives out her life taking care of Stephen's drunken widow. Sissy gets married, has children, and seems to be the only light in everyone's lives.