Final answer:
John and Michael face obstacles such as being locked out of the nursery, avoiding aviators, and the fear of harm in their attempt to find Peter.
Step-by-step explanation:
John and Michael experience several obstacles when they get separated from Peter. In the first passage, they are locked out of the nursery by Peter, which prevents them from entering the house. In the second passage, they have to escape from the chateau while avoiding the aviators who would harm them. Lastly, in the third passage, John expresses concern about the aviators possibly finding and harming Kismine. These obstacles create tension and danger for John and Michael as they try to reunite with Peter.