In The Boy in the Striped Pajamas, how does John Boyne create tension in Chapter 9?

Well,
considering the title of the book () and considering that Bruno has not met
any such boy yet,creates tension by introducing the situation in which the two boys will meet.
 This is the cliffhanger at the end of Chapter 9.  Bruno has been told that the fence of
Auschwitz is "Out Of Bounds At All Times And No Exceptions."  Bruno is not allowed to
approach the fence, explore around the fence, or get near the fence.  The fence runs the length
of the landscape as far as Bruno can see.  At the end of Chapter 9, Bruno decides to disobey his
parents and follow the fence to the right.  Therefore, John Boyne creates tension precisely by
creating a cliffhanger and allowing the character of Bruno to break the rules.  In Chapter 10,
Bruno will meet Shmuel.