Upon the demise of Sir Patrick O’Shaughlin, Thady Quirk—who quickly informs the reader that he has always been known as “Honest Thady”—must transfer his devotion to his master’s heir, Sir Murtagh. Murtagh is no Sir Patrick, that’s for sure. Had he been born some time later—or had the novel been written later—Murtaugh would routinely have been referred to as an Ebenezer Scrooge. Adding to his pecuniary parsimoniousness, he is quite literally married to a member of the Skinflint family. And when Sir Murtagh dies shortly afterward either as a result of hearing the cry of the banshee or just overtaxing himself with his argumentative personality.
And so Castle Rackrent quickly falls into the miserly hands of Lady Murtagh who almost immediately moves to divest it of any and all potentially lucrative items. That done, she flies off to London to take up residence and titleship of Castle Rackrent passes in rapid succession one more time to a new landlord: the Sir Kit Murtagh. Sir Kit turns out to be the social opposite of his brother his brother and sister-in-law. He is outgoing, warm and actually attentive to the tenants. Which makes things all the more dreadful when he decides to hand over actual management responsibilities to a thoroughly unprincipled “middleman” who manages to combine the worst aspects of sycophant and despot, almost as if he is balancing the books of his servile behavior toward Sir Kit by being wretchedly dictatorial with the tenants.
Sir Kit announces he will be arriving his bride, a wealthy Jewish heiress, and expects the castle to be fully renovated and improved. The new wife is especially troubled by the black swamp at its foreground which Kit smoothly corrects to inform her that it is known as a “bog.” She also strictly observes Jewish dietary guidelines and restrictions. Oddly enough, this is where Kit draws the line and transforms from his typically easygoing self into something of a tyrant himself. In fact, after one particularly unpleasant incident involving pork served for dinner, she retires to her room unaware of the fact that she will remain a prisoner there for the next seven years. Or course, Sir Kit isn’t really mental over pork; his wife has made it clear she can expect to enjoy none of her wealth as long as her wishes are disobeyed.
While Sir Kit essentially wins the duel with his wife, he ultimately loses the fight big time. He is forced to mortgage the castle in order to keep pace with his increasing gambling debts. Worse still, he also enjoys the ladies…which results in an actual duel with a unhappy gentlemen who succeeds in putting a bullet into his opponent.
Enter Sir Condy Rackrent, a distant cousin and the next in line to take over ownership of the castle. Condy is not without his charms especially as a master to those caring for the property. Alas, he is also quite the profligate consumer and despite the reality staring him in the face that the ancestral castle is in seriously bad financial situation, his spending does not extend to home improvements. However, things begin looking up when Condy develops a friendship with the Moneygawls. Of the Moneygawl estate, mind you. Condy becomes especially close to the family’s young daughter Isabella. There are only two flies in the ointment? One: Isabella’s father will only allow her—or anyone—to connect the Rackrents to the Moneygawls through marriage over his dead body. The other problem looms larger: Condy is actually in love with Judy, the poor niece of good old “Honest Thady.”
Such is the nature of Sir Condy’s rather relaxed attitude to life that he comes up with the perfect solution to the conundrum of whether to marry for love or money. He flips a coin. Not long after, he gets around the other problem by running off to elope with Isabella. Except that Isabella’s father has a little trick up his sleeve as well. When you can’t stop your daughter from marrying below her station, you do the next best thing: disinherit the daughter.
Life is still good for the still rather oblivious Sir Condy, however, but one must admit he knows how to make a second choice pay off. He and Isabella are living the good life, much to the continuing detriment of the now crumbling Castle Rackrent. Realizing he may be about to lose the good faith of the servants and tenants who are much more alarmed than he, Condy suddenly decides to stand for Parliament. Though he manages to win the seat, he is set to lose the castle when the creditors begin descending with serious intent and purpose.
Meanwhile, Thady’s son, Jason, has entered into the legal field and has a serious intent and purpose of his own: to eventually become the owner of Castle Rackrent himself by steadily assuming Sir Condy’s debts. Isabella’s response to this downturn in their fortunes is almost the most predictable thing in the story: she submits to all her father’s demands and returns home.
Sir Condy drafts a will leaving the entire estate to Isabella with codicil that will grant her five hundred pounds a year for life following his death. That codicil will instantly prove problematic when Jason comes around demanding payment in full of the outstanding debts. Sir Condy explains that he cannot pay off the debts precisely due to arranging for his wife’s yearly income. Jason swoops in like a vulture with his talons extended and demands that Castle Rackrent and all it estates be sold off in order to satisfy the creditors. The twin pressures of the rock on one and the hard place on the other squeeze an agreement out of Condy. Collateral damage is also suffered: Thady is overcome with despondency at the actions of his son and the two become estranged.
Things take an unexpected left turn with Isabella almost dies in a carriage accident. Jason, certain that death will arrive soon regardless, rushes to Sir Condy with a deal: sell him her yearly pension as a means of quickly raising much-needed liquidity.
And what of young honest Judy? In the wake of losing Sir Condy, she marries another. When her husband dies, she visits Condy who is now residing at her uncle’s lodge. Thady is absolute convinced that at last Condy and Judy will be married, but Judy has become something more of a woman of the world in the interim and asserts that there is little reason to marry a man with a castle who no longer has that castle. On the other hand, since Jason now owns the estate, there might perhaps be another way to assume the title of Lady Rackrent. Her uncle urges her to reconsider that idea and enters the ring on the side of Condy rather than his own son. Judy, however, is seemingly not the inheritor of her uncle’s title; rather than being Honesty Judy, she has become Scheming Judy, intent on just one goal: wealth.
Very atypically for 17th century novel, the story ends on a note of pure ambiguity. Sir Condy’s love of good times finally catches up with him when he literally drinks himself to death. Meanwhile, Isabella has not died as Jason expected, a circumstance which forces a courtroom showdown between the two over which is legally entitled to the title of the estate. Opinion is divided over whether Lady Condy will be prevail or Jason. Honest to end, Thady admits only that Judy did not wind up marrying Jason, Isabella survived the accident, but at the cost of a lifetime disfigurement to her face and, finally, that it would be nothing but pure folly to come down on one side of the other which would guarantee only stimulating ill-will toward him on the part of either Landy Condy or his son.