What are key conflict moments in the book boy striped bajamas?

* Bruno and Shmuel meet at the fence and begin to form a friendship, despite the fact that they are from very different worlds.

* Bruno's father is promoted to Commandant of Auschwitz, which brings Bruno and his family closer to the horrors of the concentration camp.

* Bruno and Shmuel's friendship is discovered by Bruno's father, who forbids Bruno from seeing Shmuel again.

* Bruno decides to go and visit Shmuel one last time, and he sneaks into the concentration camp.

* Bruno and Shmuel are caught by a group of Nazi soldiers and taken to the gas chambers, where they are killed.