I had a friend who had a playhouse in his backyard. I was afraid to climb the ladder to get inside it. I was really afraid of heights as a child but as a teenager, I attempted to force myself out of my comfort zone and not be scared anymore. It worked so now heights don't really scare me anymore.
Maybe Hattie could get Wilberforce to climb the apple tree and then push him out. Maybe not dying would help him conquer his fear.