In Dry, by Neal Shusterman, Henry and Garrett’s relationship begins with Garrett liking Henry and feeling some compassion for him. For example, when Henry is being ridiculed for being unable to help clear debris from the road, Garrett stands up for him and asks the others to leave him alone. This kindness sparked an idea in Henry: he will exploit Garrett's helpful nature. By complimenting Garrett and treating him like a grown-up, Henry is able to further build Garrett’s support. This general fondness evolves into a relationship in which Garrett sees Henry as a trustworthy older brother.
Ultimately, the reader learns that Henry has alternative motives. After purposefully building trust and admiration, Henry uses Garrett as a pawn. Henry tricks Garrett into revealing secrets about their other party members. Henry then uses these secrets in order to create conflict with the belief that it will launch him into a leadership role.
In the beginning, Garrett feels empowered and understood by Henry, because he is being treated like an adult for once. Once Garrett realizes he is only a pawn, those feelings shift to distrust and hatred toward Henry. We see Garrett’s anger toward Henry culminate when he coaxes another group member to kill Henry. Garrett's idol has now become someone he truly despises.