The Boy in the Striped Pajamas by John Boyne is a work of fiction but the historical nature of the book allows the reader to grasp far more than the book may presume. Bruno is the son of a Nazi commandant and the book and the movie trace Bruno's move from Berlin when his father gets a promotion. Without understanding the nature of the father's work, the family moves to the country and Bruno wonders about the people who work behind barbed wire. Curiously, the people there all wear striped pajamas. Bruno's curiosity will get the better of him and he will go looking along the fence where he will find Shmuel, the Jewish boy on the other side of the fence. They develop an unusual friendship which will ultimately end both their lives.
The story and the outcomes are essentially the same in both the book and movie although some subtle differences and dramatizations exist. At the end of the novel in chapter 19, Bruno who thinks they and the other "marchers" have taken shelter from the rain, stands with Shmuel holding hands and everything goes dark. There is no talk of gas chambers. "Nothing more was ever heard of Bruno after that" (ch 20). The searches all take place afterwards. It is Bruno's father's men who find Bruno's clothes by the fence.
In the movie, Bruno's mother will do the unthinkable when she notices that her son is missing and she will interrupt Bruno's father's meeting to tell him that their son is missing. The search will begin before Bruno and Shmuel have gone into the gas chamber and the movie shifts between the two scenarios of Bruno and Shmuel, ordered to remove their clothing so as to take a shower, and the frantic search. The man in the gas mask is a prominent and silent participant. Bruno's mother and Gretel will find his clothes by the fence. The father will search the camp with his men and is assumed to have made the realization at that point. In the book, it is more than a year later when he finds the gap in the fence and is presumed to have come to the same conclusion.