Montag's final battle with the Mechanical Hound may well mark his victory over the dehumanizing technology of his society that invades the private workings of man's very heart and soul. The Hound also represents the relentless pursuit of a society that would completely control lives, the sense of suspicion, the "sniffing out" of anyone who dissents or seeks to act or think independently. For, when the authorities cannot locate Montag, they "sniff out" a scapegoat to put an end to things. With great rhythm the Hound then leaps into the air and its needle strikes its mark. The poor victim falls and victory for the government is declared.
Like a fugitive from justice who has bloodhounds after him, Montag's life has been equally threatened. As he has raced through the streets his anxiety has increased because he has been terrified of being found by the Hound.
After all the running and rushing and sweating it out and half drowning, to come this far, work this hard, and think yourself safe and sigh with relief and come out on the land at only to find...
Once he has swum through the waters of Nature and found Granger, Montag knows that now he has been baptized into a real life, a life in which, as Granger says, "you leave something behind," not where things are burned.