Estraven continues to keep a diary. Ai, although he knows he should keep a record of his time for Ekumenical files, does not. Estraven keeps his diary for the Records of his Domain, and for his son.
Each man has a reason to keep an account of his journey. Although Ai’s mission is arguably more important, it is Estraven’s family who motivates him to write.
Estraven asks Ai about his family. Ai, who has spent many years traveling through space in suspended animation, is only thirty, but he was born a hundred and twenty years ago. He has outlived his parents and everyone he ever knew. Estraven has never considered this. He remarks that Ai is also an exile. Ai jokes that he is exiled for Estraven’s sake, and Estraven is exiled for his. Estraven has noticed Ai is more patient with him. He thinks perhaps the two “have learned to pull together.”
Both Estraven and Ai are united in their isolation. Both men have been separated from their families. Estraven left his Hearth under what seems to be a self-imposed exile, and left his country under a government-imposed one. Ai, meanwhile, is separated from his family by time and space. Both men are alone, but find solace as they come to better understand each other and grow closer.
For the next several days Estraven and Ai struggle to make significant progress across the rocky, uneven terrain. They are unable to move their sledge the desired twelve miles a day, but they do make personal progress. The pair begins to cooperate and communicate, compromising on the heat of the tent (Ai wants it very warm, Estraven prefers it cooler).
Although Ai and Estraven come from different backgrounds, and although Ai did not initially trust Estraven, the situation demands they work together. They are able to make their relationship work, sacrificing personal pride for the sake of their collaboration.
Estraven observes that Ai is both vulnerable and strong. He can haul twice as hard and fast as Estraven, but his mood is more changeable. Estraven respects Ai’s lack of fear and his courage. This manifests in Ai’s desire to take risky, unstable paths from the rocky ground up onto the glacier.
These risky routes do not work, and Ai and Estraven must go west, the wrong direction, in order to find an intact ice flow that will allow them to ascend the glacier. Estraven can see Ai is frustrated, but Ai does not cry in front of him. Estraven wonders why—whether it is shame, or some combination of “personal, racial, social [and] sexual” reservations.
Gethenians cry easily, as there is no social stigma against it, but Ai does not. Estraven suspects that Ai’s masculinity, which makes him take pride in his strength, also prevents him from crying because it could represent weakness.
On the twenty-third day of their journey, after twelve days of stalled progress, Estraven and Ai finally make it up onto the glacier. On the twenty-fourth day of their journey, Estraven begins to feel more confident about their chances of making it to Karhide. Unfortunately, he is entering kemmer, and being close to Ai is difficult for him. He distances himself from Ai as much as he can in their small tent, but Ai notices and asks if he has offended him somehow. Estraven, embarrassed, explains he is in kemmer.
Ai is essentially in permanent kemmer. He is constantly male, and so Estraven is stimulated into kemmer (presumably, though not explicitly stated, as a woman). Unconsummated kemmer is frustrating, and although Estraven has no choice but to interact with Ai, he does his best not to let himself get aroused, being uninterested in, or at least wary of, attempting sexual intimacy with the Envoy. Still, the pair has become intimate enough that they can discuss Estraven’s kemmer.
On the glacier, alone with Ai, Estraven feels their sexualities to be equally strange and alien. Removed from the context of Gethenian society, he sees himself as isolated and unique. Ai remarks that in the universe, Estraven’s race is sexually unique and lonely.
Estraven remarks that the Yomeshta would argue “man’s singularity is his divinity.” Ai wonders what the Handdara would say, and although they do not have a “dogma,” Estraven repeats a related song, “Light is the left hand of darkness / and darkness the right hand of light. / Two are one, life and death” joined together. Ai hypothesizes that Gethenian isolation leads them to be interested in wholeness. Estraven disagrees. “Duality is an essential” as long as there is “myself and the other” or “I and Thou.”
Estraven and Ai’s relationship mirrors the central relationship in the Handdara religion. The two do not strictly represent lightness and darkness, but they are very different, and have learned to overcome their differences in order to work together. They have managed to transcend thinking of the other man as “other,” and instead have begun to think of the other as a partner and a friend.
Estraven, made bold by kemmer, asks Ai about women, which he has never seen. Ai explains that in many societies women lead different lives than men, though it is unclear if this is because of innate or learned differences. Estraven senses “equality is not the general rule” in Terran society. Ai reveals he has begun to forget what women are like after two years on Gethen, and that women are essentially as alien to him as Gethenians.
This moment is one of explicit social commentary about “Terra” or Earth. Through Ai’s eyes, Le Guin suggests that the gender binary has made men and women feel as alien to each other as Ai and Estraven are to each other. Although men and women are the same species, Ai and Estraven are literal aliens, and still manage to find common ground.