In the book The Boy in the Striped Pyjamas, how did Boyne discuss the horror and consequences of the Nazis' final solution to the Jewish question?

I think that the premise of Bruno accompanying Shmuel hand in hand to the gas chamber is one that illustrates the horror of the Final Solution.  The idea that two children would have to meet their fate of the gash chamber is horrific enough.  The experience of Bruno's father having to find his clothes and then search for his son only adds to it.  Yet, I think that the ultimate horror that is brought out is the idea of what must have been transpiring in the boys' minds on their way to the gas chamber.  Certainly, to obtain a glimpse of this through the narrative structure reveals much in the way of the horror of the gas chamber.  Compounding this would be that the boys go off to die in the name of friendship and loyalty.  Bruno nor Shmuel ditch one another to save themselves.  Rather, they go together to meet their fate.  Friendship has transcended the fear of death.  Yet, when one has to see a noble instinct subjected to the sheer brutality of the gas chamber, I think that this does much to convey the horror involved.