The Hobbit by J.R.R. Tolkien follows the journey of Bilbo Baggins, a reluctant hobbit who is swept into an adventure by the wizard Gandalf and a group of dwarves. They embark on a quest to reclaim the Lonely Mountain and its treasure from the dragon Smaug. Along the way, Bilbo encounters trolls, goblins, giant spiders, and elves, and he finds a magical ring that grants him invisibility. This adventure transforms Bilbo from a cautious homebody into a brave and resourceful hero.