It is difficult to tell what Jess's emotions are since he is not really feeling them himself, but Paterson chooses certain details to suggest what he is feeling underneath the numbness. One such moment comes when Jess apologizes to Leslie in his mind for not inviting her to Washington with him. His feeling of guilt is clear. He is not feeling guilty because he thoughtlessly neglected to invite her, but he feels guilty because if he had invited her, she would not have died. There are flaws in this reasoning, because if the rope had not broken that day, it would simply have broken the next time they tried to swing into Terabithia, and either one of them might have died, but Jess does not allow himself to address the issue that clearly. He simply makes it all right in his mind by having Leslie, alive and well, breezily respond that she had been to Washington hundreds of times. He buries his guilt in the same way he is buried his grief, leaving only a vague trace of an immense shame.
The same thing happens in the exchange where he tells Leslie that he was scared to go to Terabithia that morning. Here, at last, is proof positive that fears are not necessarily irrational, that he does not need to blame himself for not being an entirely fearless individual. This is almost too much to handle for him. In addition to the incredible shock of having lost his best friend, he now must revise his worldview in an essential way as well. He had blamed himself so strictly for his fears, and now he sees that Leslie's lack of fear got her killed. But this, again, is too concrete a reminder of what has happened. Admitting that his fears were not senseless would be to admit that Leslie is dead, and Jess is studiously avoiding that thought. The anxiety that accompanies this line of thought provokes him to drop the whole thing and to retreat, instead, to safe recollections of his day with Miss Edmunds, when everything was perfect.
When Jess puts on his windbreaker at the end of the chapter in preparation to go over to the Burkes', it is a sign that he does understand what is happening on some level. It betrays a tacit acceptance of reality, but not a full one, as he has not allowed himself to feel anything yet. That will come later, because his grief must progress in stages, as it does for everyone.
The breaking of the rope into Terabithia is symbolic. When they first created Terabithia, Leslie had decreed that the only way to get in would be to swing on the "magic rope." Otherwise, it would simply be an ordinary woodsy area, not the magic kingdom of Terabithia. Jess feels this to be true as well. There are times when it would be easier to wade the creek, when he is carrying Prince Terrien, for example, but he always manages to find a way to use the rope, because he feels that he won't be entering Terabithia unless he does use the rope. When the rope breaks, it seems to signal the end of Terabithia as well as the end of his friendship with Leslie, and the magic will be ended then and there. The breaking of the rope becomes a tangible symbol of what had already become clear through Leslie's death.