I think that this can go in many different directions. Much of it is going to depend on your own comfort and your own sense of understanding with Bruno as a character. If you wanted to, I think that some really profound questions could zero in on the moment when he and Shmuel walk into the gas chamber. I think that exploring this with a basic, "What were you feeling or experiencing?" might bring out some really provocative questions. To explore the moments as one enters the gas chamber brings about a great deal of reflection. Obviously, asking Bruno to assess the value of his friendship at this moment might yield another set of intriguing answers that could reveal what it means to believe in something transcendent in a world that does not. Perhaps, asking Bruno about his family might also be good. Shmuel searches for his lost family, in the form of his father. Did this enter Bruno's mind as he was standing in the gas chamber, that he never got to say farewell to his own family? I think that these questions might be able to bring out more of his character and help with providing some moments of reflection about ourselves and what we would think or do if we were in the tragic position in which Bruno was.