Well, one reason could be its unique setting. The oak tree setting gives a certain charm and mystery. Also, the story often delves into themes like love, sacrifice, and personal growth in a way that really hooks readers. It shows how the characters face difficulties and change over time, which is very engaging.
Yes, there might be. Many books include stories related to nature, and an oak tree could be a central element in a story. It could be a story about the life cycle of the oak tree, or perhaps an adventure that takes place near an oak tree.
Hard to tell without reading. It could be a new challenge for the main character, a reveal of a secret, or the advancement of a subplot. You'll just have to check it out yourself to know for sure.