Chapter 3 - "The Wild Wood"
Months after meeting Toad, Mole is curious about meeting the elusive Badger. He had hoped Badger might show up at Rat’s house, but Rat keeps reminding Mole that Badger prefers solitude.
As winter approaches, Rat begins napping for long periods of time, leaving Mole with the opportunity to sneak off into the Wild Wood to search for Badger himself.
At first, Mole enjoys his afternoon stroll into the Wild Wood. Soon enough, though, the woods become haunting, as Mole begins to notice faces staring at him from holes in the ground. He then hears the terrifying patter of animals approaching, and he hides. He realizes he is in the midst of the Terror of the Wild Wood.
Meanwhile, Rat wakes from his nap and realizes that Mole is gone. He notices Mole's footsteps leading to the Wild Wood, and packs some gear - including guns - to search for his friend. After hours of searching, he finds Mole deep within the woods. They start to return, but Mole is exhausted and needs a quick nap before continuing.
Unfortunately, it starts snow during their nap, making the woods even more difficult to navigate. The two wander for hours, until they eventually stumble upon Badger’s home.
Chapter 4 - "Mr. Badger"
Badger welcomes the two freezing animals inside, even though he is preparing for bed. He stokes the fire and gives them a full dinner, ignoring their bad table manners because of their hunger.
They all stay up late, talking. When Badger mentions Toad, Rat reports that he has recently wrecked seven motor cars, and has been hospitalized three times. Apparently, Toad insists on driving himself, certain that he is a good driver. Badger makes Rat and Mole promise that they will all visit Toad in the spring, to convince him that his childish actions will either ruin, bankrupt, or kill him.
The next morning, Mole and Rat wake in Badger's home. In the kitchen, they find two young hedgehogs eating oatmeal. The young animals had gotten lost in the snowstorm on their way to school, so Badger invited them to weather the storm there until it was safe. The hedgehogs explain that Badger has already eaten, and is spending time in his study.
While breakfast is cooking, Otter comes through the door, with news that the river animals are worried about Rat and Mole’s disappearance.
Badger finally joins the group. He sends the two hedgehogs back home since the storm has stopped, and gives each of them a little money as a gift. Afterwards, he tours Mole around the house while Otter and Rat discuss the river. As they look around, Badger and Mole agree that they feel more comfortable underground, that living beneath the earth is easier than trying to build a house above ground. Mole asks Badger how he built such a grand home, and Badger admits that he found it, rather than building it. Before the woods became the Wild Wood, it had been a human town. The humans had initially pushed the animals away, but eventually abandoned the town. Now, animals have reclaimed the environment as their own.
Mole and Badger return to the other animals, and Otter then leads Mole and Rat back to the river through one of Badger’s tunnels.
The major theme of Chapter 3 is experience and maturity. Rat and Mole deal with difficult situations in different ways, since they are at different phases of life. Because Mole exemplifies a young man trying to make his way in the world, he does not heed Rat’s warnings about the Wild Wood. Like a child, he does not have a sense of consequences, and instead acts from impatience. Moreover, he knows that Rat would criticize his decision; he leaves while his mentor is asleep, in order to avoid censure.
And as often happens with children, the adventure does not immediately have consequences. Mole's adventure is initially pleasant and fun. However, the reader - who sees the situation from outside Mole's limited perspective - can tell that danger is coming through the foreshadowing of the wintry scenery. Winter is synonymous with abandonment and isolation, situations Mole soon finds himself in. The consequences might not be clear right away, but they eventually become apparent, and Mole is stuck with no way to solve the situation. He is too young and inexperienced to navigate the Wild Wood alone.
Rat, on the other hand, displays his maturity as soon as he realizes what Mole has done. Without hesitation or anger, Rat gathers his supplies and heads toward the Wild Wood to find his friend. Because he does not give up, he finds Mole. Even once the situation becomes difficult - Mole needs to rest and the snow is continuing - he acts with equanimity, understanding that anger will not help them navigate the situation.
Grahame does suggest, however, that we are reliant on luck and circumstance to some extent. For instance, it is pure luck that Mole trips over Badger's door scraper. And yet it is important that we respond to such circumstance with intelligence and maturity. Rat wisely determines that a door must be nearby, and takes the time to model how Mole can deduce such facts from what he sees. They might have stumbled on luck, but it took wisdom to capitalize on that luck.
Another consequence Mole has to face is his friend's exasperation. Once he has resolved the danger, Rat reveals his temper, as adults often will with younger children. Mole's tactic to return to Rat's good graces - flattery, in the form of a monologue praising Rat's brilliance - suggests that pride is a human emotion, one that people of all ages are susceptible to.
Chapter 4 introduces the novel's final main character, Badger. All we know about Badger thus far is that he is a solitary, gruff animal. He seems to show very little humor. When he realizes that Rat is out in the cold, however, he shows that such characteristics do not entirely define him. Instead, he reveals his true caring nature by inviting the cold animals inside, and changing his bedtime plans in order to accommodate them. Despite being somewhat grumpy and isolated, Badger nevertheless feels duty-bound to his friends (and other people in need, like the hedgehogs). Badger represents the rugged man, someone who is self-sufficient and honorable despite a gruff exterior. Grahame is reminding us that we cannot always judge someone by their outward characteristics.
However, Grahame does pass judgment on Badger for his carelessness in terms of proper etiquette. When Mole and Rat eat quickly, they stray from their manners, placing their elbows on the table. Badger ignores this slight of politeness; he is not concerned about such things. However, Grahame instructs us through an aside that such an attitude is improper. Yet again, The Wind in the Willows veers from its plot in order to act as a manner guide for children. While we might not today emphasize manners to the extent Grahame does, it is nevertheless interesting that he wants us to see Badger in terms of his contradictions, and not just as a simplistic, static character.
Chapter 4 is also interesting because it features multiple instances of reverse anthropomorphism - a device whereby animals who are generally treated as humans show their natural animal traits. Here, we see the animals showing traits unique to their species. For instance, Rat feels confined underground at Badger's house, anxious to be separated from water and open air. Mole, on the other hand, feels more comfortable. While he loves learning from Rat - as humans do - he also feels drawn to an underground environment - as Moles do. It is an intriguing aspect of the novel, that the animals can be so human and yet remain tied to their animal natures.
Finally, Grahame continues to celebrate the pastoral life as superior. Even when nature is dangerous - as it is in the Wild Wood or in the snowstorm - it is marked by beauty and wonder. One lives and thrives at the mercy of great forces. On the other hand, a life of industrialism is temporary and short-sighted. This latter message is delivered through Badger, who explains how humans had abandoned the town where the Wild Wood now stands. He explains the process as cyclic: humans will always come to an area and force out its wildlife, build their unnatural structures, and then abandon the area, at which point animals reclaim their original home. There is something depressing about the idea that humans would destroy something only to later desert their winnings. Grahame sees industry and cities as wasteful and temporary, whereas nature perseveres, reviving itself time and again in a holistic, inherent way.