When we're first introduced to Will's cousin Henry in The White Mountains, he comes across as nothing more than a fairly one-dimensional bully with whom Will gets into regular fights. Truth be told, Henry is no friend of Will's. In fact, as Will states quite explicitly, the two cousins have hated each other for as long as he can remember.

By the time we come to the end of the novel, however, the relationship between Will and Henry is a lot more cordial. And no wonder, because the two have shared an awful lot of danger and hardship together as they embarked upon the long, hard trek to the White Mountains, a place where people are free from being capped by the Tripods.

Yet the relationship is not all plain sailing. Residues of mistrust and mutual loathing still remain. At one stage of the journey, Will wakes up to find his pack gone and immediately concludes that Henry has taken off and abandoned him. As it turns out, Henry only left to get some food and had hidden Will's pack for safety.

Towards the end of the story, however, when his arm has been seriously injured and he is in considerable pain, Will openly acknowledges Henry's kindness in saying that he would've shrieked a lot more had he been in the same pain. This is a sign of just how much Will's opinion of his cousin has changed over the course of the book.