How does Shmuel end up in Outwith?

Shmuel tells Bruno about how he came to live at Out-With. He tells bruno that his family was forced to move to a different part of Cracow, where they lived all cramped up with another family. Then he tells Bruno that one day soldiers arrived and packed him and everyone living nearby into huge trucks. Lots of people hid from the soldiers, but Shmuel believes they were all eventually found. They were brought to a train, which Shmuel says "was horrible... there was no air to breathe. And it smelled awful" (129). Bruno tells him that he should have gotten on the train Bruno took, the one on the other side of the platform, but Shmuel says his train had no doors. Bruno doesn't believe him about that detail, either. Shmuel tells him that when they got off the train, they all had to walk to Out-With; Bruno counters that his family "had a car" (130). He cannot understand why Shmuel seems so sad, since "after all much the same thing had happened to him" (130).