Compare Christopher’s encounter with the policeman in these chapters to his first encounter. What has changed? What is the same?

By chapter 11, Chris no longer feels threatened by the policeman. Christopher calms himself down by - among other things - distracting himself with math problems, putting his hands over his ears and pretending he is in a computer game. After a while a policeman comes up to him and tells Christopher that he has been there for two and a half hours and was acting like he was in a trance. Christopher feels safer with the policeman and answers all of his questions. The policeman takes him to the ATM to get money for the train, and shows him where to get his ticket. Christopher then walks through a difficult underpass and boards the train.