Dioneo expresses relief that the terrible stories of star-crossed lovers have finally come to an end, since he has no desire to add to the collection. Instead, he promises a more agreeable theme. In Salerno, Doctor Mazzeo della Montagna marries a beautiful young woman in his old age. Because he’s rich, he keeps her in fine style, but Mazzeo’s Wife often feels chilly at night because he fails to keep her properly covered.
Dioneo’s tale begins with a familiar setup: the old husband who can’t satisfy his beautiful wife. While Dioneo’s tales usually provide a humorous end to the day, nowhere is it more necessary than at the end of Day 4’s collection of tragedies. The oddly circumspect language with which he cloaks his discussions of sex in this tale, beginning with the metaphor of Mazzeo’s insufficient sexual power as a too-small blanket, adds to the humor of one of his silliest tales.
Like Ricciardo di Chinzica (from Dioneo’s story on the second day), who used a calendar of saint’s days to keep from having to bed his wife too often, Mazzeo della Montagna tells his wife that so many days are necessary to recover from making love to a woman. Frustrated, Mazzeo’s Wife decides to protect her husband’s family jewels by polishing someone else’s. She settles on Ruggieri d’Aieroli, a nobleman who has led such a disreputable life that all his friends and even his family have disowned him.
Dioneo’s explicit reference to his own earlier story emphasizes the tales’ interconnected nature; The Decameron is a carefully planned and arranged work. Unlike Ricciardo, however, Mazzeo relies on the authority of medicine, representing human ingenuity, rather than religion when he claims that a certain number of days are necessary to recover from sex. While this ties in with medieval medical ideas about the depletion of physical energies, it also points to Mazzeo’s age, implying that a certain number of recovery days are required for men who are old and not very powerful lovers. Mazzeo’s wife’s lack of concern for Ruggieri’s bad reputation since he has a good body is an exception to the book’s general preference for true character rather than appearances.
After Mazzeo’s Wife and Ruggieri d’Aieroli have been lovers for a while, Mazzeo della Montagna happens to receive a patient who needs an amputation. He plans to perform the surgery in the evening and orders a bottle of anesthetizing potion, which he leaves sitting on a windowsill. Just as he’s getting ready to operate, he gets called away on a more urgent matter, allowing his wife to invite Ruggieri over.
The amputation scenario bears all the hallmarks of fortune’s caprice, since it provides a reason for Mazzeo to leave the house and pointedly introduces a sleeping potion to the story. It's also a realistic reminder of how harsh medical treatment could be in the Middle Ages.
Arriving at the house quite thirsty, Ruggieri d’Aieroli spies the bottle of potion and drinks it all down, which puts him out cold. When Mazzeo’s Wife comes to the bedroom, she can’t wake him, and she becomes alarmed when he sleeps through a fall from the bed to the floor. Unlike her husband, she’s not a great physician, so she concludes that he’s dead, and after a few minutes of weeping, she begins to think about what’s necessary to protect her honor. She summons her Trusted Maid to help her.
Ruggieri’s great thirst and lack of attention to what he is drinking suggest a hint of gluttony or excessive consumption in his character, so the misfortunes that befall him later in the story can be interpreted as “punishment” for this vice. Although Mazzeo’s wife seems genuinely upset to discover him as if dead, she quickly turns to the practical matter of protecting her honor, since maintaining it is necessary for her safety—especially after a day’s worth of tales that have highlighted female vulnerability to male violence and revenge.
Trying to settle on a place to leave Ruggieri d’Aieroli where his death won’t implicate them, the Trusted Maid suggests that they put him into a trunk that’s outside of a nearby carpenter’s shop, stab him a few times to make it look like someone else’s foul play, and leave him. Mazzeo’s Wife categorically refuses the stabbing but likes the trunk idea. They carry him out and stuff him into the trunk.
Had they followed the trusted maid’s plan, the women would have accidentally murdered Ruggieri. And while this might have been the outcome of the tale if told by any of the other members of the brigata, since Dioneo has special dispensation to tell the tales he wants, the tragedy is easily averted by the wife’s refusal to abuse what she believes to be a corpse.
But two Money-lenders, recently arrived in the neighborhood, decide to steal the trunk because they need furniture and they’re too cheap to buy it. Although it’s heavier than they expect, they carry it home under the cover of darkness. Ruggieri d’Aieroli eventually wakes up, although he’s still somewhat muddled. He can’t move or see, so he’s not sure if he is awake, asleep, or dead. He tries to roll over, overturning the trunk and tumbling out.
Because moneylenders earned their living by charging interest (sometimes at excessive rates), they were generally distrusted and disliked in medieval society and they often came from marginalized groups. These moneylenders live up to the stereotypes of their profession by being dishonest (they steal the chest that’s been left in the open) and penny-pinching (they steal it because they don’t want to spend money on furniture).
The Money-lenders sleep through this commotion, but their ladies hear the crash and the sound of Ruggieri d’Aieroli stumbling through the dark. They wake the neighbors with their screams of “Burglar!” A confused and astonished Ruggieri is quickly arrested and taken to the magistrate, who tortures him into confessing that he intended to rob them.
Ruggieri’s evening is certainly not going as he expected it to. But sometimes, when one’s fortunes go from bad to worse, it’s a source of humor rather than tragedy.
News of Ruggieri d’Aieroli’s arrest spreads quickly through Salerno, much to the astonishment of Mazzeo’s Wife and the Trusted Maid, who were sure that he was dead. They start to suspect that maybe the previous night’s events were a dream, until Mazzeo della Montagna returns home and demands to know who moved his sleeping potion. Suddenly understanding Ruggieri’s state the previous evening, Mazzeo’s Wife sends the Trusted Maid out for news. The Maid reports that the judge plans to execute him, and none of his friends or family show any intention of helping him out. She also discovers that the Money-lenders had taken the trunk into their home.
Mazzeo’s return marks the moment when Ruggieri’s fortunes, recently brought low, begin to shift. Although she didn’t have the medical skill to realize that Ruggieri was not dead but merely drugged, Mazzeo’s wife is nevertheless clever, as demonstrated by her quick realization of how the pieces of the previous night’s puzzling events fit together. Sending the maid out for more information is another sign of her wisdom.
Mazzeo’s Wife begs the Trusted Maid to help her save Ruggieri d’Aieroli without revealing the affair. The maid goes to Mazzeo della Montagna and tells him that she’s been having the affair with Ruggieri, to whom she gave the potion under the impression it was water. She’s very sorry and worried about the price Ruggieri is going to pay for her mistake. The doctor is angry to hear about the affair but can barely keep from laughing at the image of the maid being disappointed when her lusty lover turned into a drugged “slug-a-bed.” Warning her to keep Ruggieri away in future, he forgives her and sends her to the judge to finish straightening things out.
While the first concern of Mazzeo’s wife on finding her lover “dead” was to protect her honor by getting rid of the body, she doesn’t value her maid’s honor highly at all. In fact, she treats it as disposable when she asks the maid to confess to the affair in her place. Mazzeo’s anger over the maid’s alleged dalliance—and his insistence that she break it off, or at least not dishonor his house by meeting with her lover there—confirm his wife’s wise strategy, since they suggest that there would have been dire consequences if he had realized that she was actually Ruggieri’s lover.
The Trusted Maid wheedles her way into an interview with the judge, and because he thinks she’s a “tasty dish,” he asks for a nibble before hearing her case. Knowing this will incline him to generosity, she gives him a snack without any objections. Then she picks herself up and tells him the same story she gave the doctor. The judge summons Mazzeo della Montagna, the carpenter, the Money-lenders, and Ruggieri d’Aieroli for testimony, and after hearing all the evidence, he finds Ruggieri innocent. Ruggieri, the Maid, and Mazzeo’s Wife have many a laugh about the story, and their love continues to flourish.
Like the other judges and magistrates in Day 4’s tales, this judge uses his power to extort sex from vulnerable women (compare to the Duke of Crete in III, 3 and the judge who pursues Andreuola in III, 6). The maid is more than happy to give him what he wants, illustrating misogynistic stereotypes about women as excessively lustful and unconcerned about their virtue. And, because she is a maid, not a fine lady, her honor isn’t as valuable as her mistress’s.