Montag is initially engaged in his typical fireman duties, which involve setting fire to houses that contain books. However, beneath the surface, there are seeds of doubt and a growing sense of disillusionment within him.
Montag changes a lot. At first, he's just another cog in the machine, but through various experiences and encounters, he develops a sense of independence and a desire for truth, completely transforming his outlook and actions.
At the end of the novel, Montag encounters a group of like-minded individuals who are dedicated to protecting and sharing knowledge in a world that has suppressed it. They provide him with a sense of belonging and a purpose beyond his previous existence.
Montag's transformation since the start of the novel is profound. Initially, he blindly followed the rules, but later, he became enlightened, started reading books, and fought against the oppressive system.
Guy Montag is described as a middle-aged man with a rather ordinary appearance. He has nondescript features and a somewhat worn-out look due to the stress of his job and the dystopian world he lives in.