The first half of this chapter shows us Kusanagi closing in on the trail of Ishigami. The second half shows Ishigami increasingly careless and impulsive in his handling of the case, contrary to his usually logical manner. He rents a car, knowing better than to leave a paper trail like this. He clumsily shadows Kudo and gets caught spying on Kudo from the anonymity of his rental car. He also writes a threatening letter to Kudo, which, if sent to Yasuko, will clearly result in Ishigami becoming a suspect in the case, as the letter also threatens to kill Kudo just as Togashi was killed. The tension increases as Kusanagi and Yukawa get closer to the truth while Ishigami seems to unravel and become increasingly desperate as his jealousy clouds his judgment.

When Kusanagi goes to Shinozaki Station, we find Yukawa eating an ice cream cone as he casually leans against a guardrail. His taste for sweets is reminiscent of the character L in Death Note, who is constantly munching on some kind of snack or pastry, or Toshiro Mifune's character in Sanjuro, who lies on the ground and casually eats a snack while the more naive samurai maintain formal etiquette. Eating habits often give insight into people's character. Sweets and other such foods don't seem to fit the image of a stodgy, mature professor. Rather, they show a disregard for the rigid social conventions that dictate how and what a person is supposed to eat, particularly in Japan where etiquette in regard to eating behavior is quite well-developed. Other than sweets, Yukawa is constantly found drinking instant coffee, his cup grimy and unclean, to the disgust of Detective Kishitani and other visitors who are offered coffee. His penchant for drinking instant coffee from a grimy cup shows Yukawa's devotion to physics, which often requires staying up late into the night, as well lack of regard for social norms governing hygiene and people's dietary behaviors.

Yukawa very much maintains a youthful demeanor, indicated not just by his love for sweets but also by his persistent presence in his lab where, accompanied by his graduate students, he pulls all-nighters and forsakes the bodily requirements of sleep. His love for badminton, which he plays on a regular basis with college students, also betrays his youthful spirit, underscored by the fact that Kusanagi, Yukawa's former badminton partner, has long since given up on the sport, being too busy with his work. While an undergraduate student, Yukawa's hippieish image is evident through his overgrown shoulder-length hair. Ishigami also remarks how amazing it is that Yukawa's has kept a full head of hair and looks just as healthy and vigorous as he did in college. While waiting to meet Kusanagi, Yukawa's clothing consists of simple white pants, a long-sleeved blackshirt, and a fashionable pair of sunglasses. Perpetually in his lab and among graduate students, Yukawa seems to have never matured beyond the habits of college student days, retaining his youthful energy and carefree attitude towards dress, food, posture, hair, and other life habits.

Aside from his non-conventional life habits, his style of conversational repartee is just as non-conventional. He enjoys speaking in a roundabout way, giving indirect answers to simple questions as if to poke fun at the formulas and conventions that dictate how people are supposed to engage in dialogue with each other. When Kusanagi asks him, "What are you doing here?", Yukawa responds playfully, "Waiting for you," which evades the obvious purpose of Kusanagi's question.

His usual playful responses will cease, however, when Kusanagi demands to know what Yukawa knows about Ishigami's involvement in the case. When asked about this, Yukawa turns serious and grim. The sudden change in his demeanor serves to underscore the inner conflict he feels: a desire to protect his old friend Ishigami on the one hand along with a desire to help his friend Kusanagi on the other.

"I'm afraid I won't be giving you my full cooperation with this case. I'm looking into it for personal reasons," says Yukawa, parting ways with Kusanagi. As Kusanagi and Yukawa diverge from each other, it shows how human emotions can override people's desire to remain logical and cool-headed about matters, a theme of this chapter. Both Yukawa and Ishigami, usually level-head and stoical geniuses who don't seem prone to the same kinds of emotional excesses as other people, are overcome by intense emotion in this chapter, which in turn causes them to act against their better judgment or behave in atypical ways. In Yukawa's case, Yukawa refrains from cooperating with Kusanagi and shows himself to be stiff and even somewhat hostile, in contrast to his usual playful banter. In Ishigami's case, it is jealousy that clouds his judgment and causes him to diverge from the strict arrangement and protocols he developed to help cover up Togashi's murder.

Just as Kusanagi begins to suspect Ishigami's role in the case, which could lead to his Ishigami's downfall, Ishigami is now seen stalking Kudo. From the reader's point of view, there seems to be no doubt about the sordid motives that lead Ishigami to follow Kudo. This would seem to diminish Ishigami's stature in the eyes of the reader, as he had mostly maintained a respectful distance from Yasuko up until now. Ishigami is filled with jealousy as ne notices with admiration the nice clothes that Kudo wears and his photogenic appearance in the pictures that Ishigami takes while shadowing him. Furthermore, he writes a threatening note to Yasuko, demanding that she break her relationship with Kudo. The note is to be accompanied by the two photos that Ishigami has secretly taken of Kudo.