Complex sentence: He is writing a letter to Jason which he is going to post on the trees around the forest, hoping his son reads the letter, realises that his father has undergone a transformation, and comes home to him.
Split into simpler sentences: He is writing a letter to Jason which he is going to post on the trees around the forest, hoping his son reads the letter. Jason realises that his father has undergone a transformation, and comes home to him.