What does Carle realize on the second night of the rescue attempt? How does he change as a result?
It is not specifically stated what Rolf Carle realises on the second night, but it is inferred that Rolf is beginning to seriously worry about the chances of saving Azucena. What is clear is that the relationship that they are forming transforms Rolf Carle, forcing him to confront memories of his childhood that perhaps he had repressed or deliberately forgotten:
That night, imperceptibly, the unyielding floodgates that had contained Rolf Carle's past for so many years began to open, and the torrent of all that had lain hidden in the deepest and most secret layers of memory poured out, leveling before it the obstacles that had blocked his consciousness for so long.
It is clear that something about confronting the suffering and perhaps hopeless case of Azucena triggers off a similar reaction within Rolf Carle himself - he has to face his own terrible past and events that severely impacted him - he cannot hide any longer:
There, beside that hellhole of mud, it was impossible for Rolf to flee from himself any longer, and the visceral terror he had lived as a boy suddenly invaded him.
Rolf draws a direct parallel between the situation of Azucena and his own situation at own age. He, like her, was metaphorically "trapped in a pit without escape" and "buried in life". This realisation initiates an epiphany about himself. He realises that all of his achievements as a reporter "were merely an attempt to keep his most ancient fears at bay, a stratagem for taking refuge behind a lens to test whether reality was more tolerable from that perspective." Finally, Rolf Carle has to face reality because of the connection he feels with Azucena - he can hide no longer.