Beauty’s life in Earlshall, while not terrible, is nothing like Birtwick. At this hall his master’s wife demands that all her horses wear the check rein, a device which forcibly holds up the horse’s head, causing it lasting pain and undercutting its pulling strength. She forces the coachman—Mr. York—to put check reins on both Ginger and Beauty. Ginger eventually rebels against this measure and attempts to kick free but is subdued by the grooms. So the two horses become accustomed to this discomfort. When the family temporarily leaves the hall along with Mr. York, Reuben Smith becomes the temporary caretaker of the horses. This man is highly skilled and knowledgeable about taking care of horses, Beauty notes, yet he has one fatal flaw: he has a drinking problem. This issue changes the course of his life and Beauty’s when one day, riding back towards the hall in a drunken state, Smith fails to properly maintain Beauty’s shoes. This results in Beauty’s legs collapsing part-way through the journey, throwing Smith off and killing him. Beauty himself has to undergo a painful medical procedure which leaves his legs permanently scarred. The Earl decides he cannot keep a horse in such a scarred state so he sells Beauty; Beauty goes through a number of buyers until he ends up a job horse to be rented out by drivers. Here for the first time he encounters bad drivers, and, because these drivers often do not know how to properly drive or take care of horses, he receives long-term physical harm. Eventually though a gentleman who takes pity on Beauty convinces his friend to buy the horse and so Beauty becomes the property of Mr. Barry. This fellow, while a good man who orders that the horse be treated well, fails in his selection of caretakers for the horse. Twice he hires grooms who, when Mr. Barry is not watching, behave in ways which further hurt the horse. Mr. Filcher—the first of the two—steals food meant for Beauty and uses it for his own commercial purposes. Alfred Smirk—his replacement—acts as if he knows how to take care of horses but in reality leaves Beauty’s stall in such terrible conditions that the horse becomes ill. After uncovering this second deceptive groom, Mr. Barry decides not to keep the horse at all and instead sends Beauty to be sold at a horse fair.
At the horse fair, Beauty comes dangerously close to becoming the property of a mean, cruel-looking man; but in the end, a kind and empathetic man buys him. This man is Jeremiah Baker—though he goes by Jerry. He works as a cab driver in London and though he does not make much money, he makes enough to feed his wife and son and daughter and to take good care of the horses. Jerry and Beauty take a strong liking to each other right away, and soon Beauty comes to the conclusion that Jerry is the best man he ever knew. Always gentle, cheerful and adept, he helps Beauty adapt to the otherwise disheartening life of a London cab horse. The two, along with Jerry’s other horse—Captain, an old, dignified warhorse—have several adventures together. On one occasion a woman approaches Jerry asking for directions to the hospital to get medical help for her child. He insists on driving her there himself free of charge, and this act of kindness immediately brings returns to Jerry: as soon as he drops her off, he picks up another customer, this time his wife’s old mistress, who offers to find Jerry a less strenuous job and gives him a gift of ten shillings. On another occasion, Jerry—who normally never works on a Sunday as he is a religious man who preserves the Sabbath—agrees to take a woman on Sunday to her dangerously-ill mother outside the city. This act too immediately pays off for Jerry, as he and Beauty—while waiting to bring back the lady--enjoy the beautiful meadow next to the mother’s house in the countryside. This happy part of Beauty’s life, too, comes to an end. In the third winter they are together, Jerry becomes severely ill, nearly dying. His doctor tells him not to go back to the cab business, so he decides to look into the old mistress’s employment offer. With great delight, the family soon receives the news that they will indeed work for this lady, and that they will be living in the country in a nice cottage and Jerry will there be a coachman and receive a comfortable salary. This delight is bittersweet, as it means leaving behind their beloved horse Jack—their name for Black Beauty—and their departing is just as bittersweet for the horse as well since he is happy for their prosperity but sad to leave them and apprehensive about his own future state.
After making a thorough search for a buyer who would be kind to his horses, Jerry decides to sell Beauty to a friend of his who works in corn dealing. His stay there would have been quite pleasant, Beauty notes, had this principled corn dealer been on the premises to watch out for his horses. The problem though was that when he was not on the premises, the foreman would overload the horses in order to increase the productivity of the business. As the foreman continued, day after day, to overburden the loads of the horses, Black Beauty and the other horses began to physically wear out. Soon enough, Black Beauty becomes too weak to work much longer there, and his owner sells him to a cab business owner named Nicolas Skinner. This man employed cab drivers and rented out the horses to them on a daily basis. He was exploitative of these men and they in turn were exploitative of their horses, as they had to overwork the horses to make enough money to pay off the rental fees. At no point in Beauty’s life does he suffer more than at the hands of these harsh-handed men. He continues to try his best though until his health simply deteriorates. Skinner, having sucked out what benefit he could from the horse, sends him to a horse market. Much like the previous story of the horse market, another kind man takes a liking to Black Beauty and buys him. This time it is Farmer Thoroughgood, who buys the horse under the encouraging of his little grandson Willie and decides to nurture him back to health before selling him again. The farmer and his grandson take excellent care of Beauty, and the horse, having just come out of the hardest part of his life, begins to feel happiness again. Although Beauty is by now an old horse, he fully recovers and Thoroughgood takes him to potential buyers. These buyers are Miss Blomefield and Miss Ellen, who live in a pleasant house in the countryside. They took a liking to the horse despite the scars on his legs from his old injury. Their groom also approves of the horse, and so they buy him from Thoroughgood. When the groom then begins to clean Beauty, he notices a few of the horse’s white marks on his otherwise black coat and he says to himself that this horse looks an awful lot like old Black Beauty. As he continues, the marks become unmistakable and he exclaims in joy that this must be Black Beauty and that he himself is Joe Green, Beauty’s old and dear friend from Birtwick. Joe is now a young man and Beauty an old horse, yet there old friendship immediately resurfaces. As it turns out, the ladies of the house are benevolent masters, Joe is an excellent groom and little Willie continues to visit his new friend Beauty frequently, so Beauty finds great happiness and peace in his new home. It is here that the story ends. Beauty is at peace, saying that often now, before he becomes fully awake, he feels like he is again under the trees of the orchard, standing contentedly with his old friends and talking with them.