While in court, Peak hopes and thinks that his father was there to help him and take him out of the mess they were in. Peak thinks that Josh is someone caring and thoughtful and that he is there to help him and feels some emotion towards him. This makes Peak think good, positive thoughts about Josh, his dad.
When Peak arrives back at Base Camp from ABC, he find out that the reason for why Josh came to New York was so that he could help himself to Peak, and not actually help Peak and his family. Josh came to New York so that he could lure Peak in and use him (getting to the top) as publicity for his struggling business.
Towards the end of the book Peak decided that climbing can be a hobby of his, but that he will always prefer to be back home with the twins and his mum and step-dad. He tells Josh that this climb was his last one, because he misses his family and old life back so much.