This is an action-packed episode full of tension and suspense. Yasuko, in order to save her daughter, strangles her ex-husband to death. Misato likewise becomes an accomplice to this murder, not only by having initially struck Togashi with the flower vase but also by having aided her mother in strangling Togashi by scratching at his fingers. This creates a dilemma for Yasuko: if she turns herself in, Misato will be without a mother and will also have to bear the stigma of having a murderer for a mother. If she turns herself in and attempts to hide Misato's role in the murder, it is likely that the police will find out what happened, which might incriminate Misato. Fortunately, at just the right time, Ishigami arrives on the scene to help her.

Ishigami does not pressure her into take one course of action over the other. If she chooses to turn herself in to the police, he won't stop her. If she chooses not to turn herself in, he is willing to help her dispose of the body and cover up the crime. At no point does Ishigami impose himself on Yusako in order that she might be in a position where she is in debt to his kindess. This is an important detail for later on. Suffice it to say that Ishigami in no way uses coercion or tries to manipulate Yusako into accepting his aid, which shows his character to be respectful of Yusako's autonomy and independence. This is in stark contrast to Togashi, who frequently imposed himself on Yusako and persistently manipulated her with belittling insults, guilt-tripping, begging, appeals to her sense of pity, and even threats to harrass Misato. Whereas Togashi made himself a persistent nuisance in Yusako's life so that he could benefit himself, Ishigami has voluntarily placed himself at her disposal with no expecation of anything in return.

Ishigami's manner the whole time is one of cool-headed self-control and dispassionate concern about the practical aspects of the case. As Yusako notes, his tone and manner have the quality of a professor teaching his students. In Chapter 1, we are given an inkling of Ishigami's powers of deduction as he anaylzes the life situation of each of the homeless people and other casual bystanders that cross his path on the way to work. In this chapter, these same powers of deduction are on full display and brought to bear on the task of covering up the murder. He is able to fully deduce exactly what transpired in Yusako's apartment, and the reader is full of anticipation and suspense as to what kind of plot he will develop to hide the murder.

Despite his apparently cool-headed manner, towards the end of the chapter, we are also privy to some of the deeper motivations arising from the Freudian id:

I have to protect them, thought Ishigami. He would never this close to so beautiful woman ever again in his life. While examining Togashi's lifeless face, he is filled with jealousy at Togashi's handsome features:

And Yasuko fell in love with him. When Ishigami thought this, it was like a bubble poppsed inside him and envy spread through his chest. When Yasuko sighs with exasperaion, Ishigami's reaction is creepily one of sexual arousal:

Yasuko sighed. To Ishigami, it sounded sexual, almost like a moan, and his heart fluttered. I won't let you down, he thought, steeling his resolve anew. While Ishigami's involvement has been non-coercive and seemingly altruistic, there is a more carnal and distinctly human aspect to his motives, as the quotes above demonstrate. He is not merely the flat, level-headed professor driven strictly by scientific curiosity who he appears to be on first glance. He is prone to human sentiments such as jealousy and sexual attraction like anyone else. This gives rise to a certain degree of ambiguity on the part of the reader towards Ishigami: on the one hand, his intervention is much appreciated and comes at the most opportune time. On the other hand, the primeval side to his motives raises suspicion about whether or not he might just be taking advantage of a situation for his own selfish interests.

Nonetheless, regardless of what the true nature of Ishigami's motives are or what kind of primeval psychic forces are compelling him to act in the way that he does, there is no question that he regards the situation as a complex math problem:

He was sure their problem had a solution. Every problem had one....Ishigami closed his eyes. It was a habit he had developed when confronting ornery mathematical challenges - all he had to do was shut out all information from the outside world, and the formulas would begin to take shape. Except this time, it wasn't formulas that filled his head. There is spiritual quality to Ishigami's ability to contemplate mathematical problems, and it's not for nothing that he is nicknamed the "Buddha," as we will later find out. His last words to Yasuko are:

Trust me. Logical thinking will get us through this. Ishigami is the logical thinker par excellence. It will take someone of equal intellectual prowess to match his wits and confound his plans. The groundwork has been laid for a mystery whose jigsaw-like quality will be a source of constant curiousity for the reader.

A couple of minor technical inconsistencies are worth considering here, though they do not detract from the overall flow of the story, nor do they detract from Higashino's technical execution of the story., which is for the most part quite thorough.

One wonders if minors such as Misato would be charged for actual murder, but it's certainly part of the minutiae of Japanese law that will not be considered here.

Having been beaten by Togashi, Misato would most likely have bruises or marks indicative of such an experience, but this will not become an issue later on.

Ishigami is made out to be whole-hearted math geek whose sole passion in life is math. His involvement in the Judo club seems questionable. It seems like a plot device that helps account for his ability to move the corpse and accomplish other tasks necessary for the plot, as we will see later.

Aside from Ishigami, it seems like there could have been other neighbors in the apartment building who could've heard what happened. Yasuko herself mentions the possibility "the neighbors" (plural) overhearing what happened. While Ishigami remarks that the building is mostly soundproof, it seems unlikely that they would not have at least heard vague thuds or other noises. They might have at least seen Togashi entering the apartment building.