It is ironic that Captain Beatty has ordered the mechanical hound to search for Montag because at one time Montag was a fireman who use to burn books along with Beatty and the other firemen. The mechanical hound is programmed to sniff out people who have books, and at the beginning of the novel, the hound seems to sense something about Montag. Captain Beatty notices it and tells Montag that it seems the hound doesn’t like him. This conversation foreshadows the eventual hunting down of Montag by the mechanical hound after Montag burns down his own home and turns the flame thrower on Beatty. The mechanical hound that has come with Beatty is able to inject Montag’s leg making it numb. Montag turns the flame thrower on the hound, and fortunately, Montag is able to run to Faber’s house to warn him. Faber gives Montag old dirty clothes to help change Montag’s scent. Montag escapes the city and is able to avoid the second hound that is sent after him because when he meets up with Granger and the hobos, Granger gives him something to drink that will change his scent as well.
It is ironic that Beatty and the mechanical hound are searching for one of their own when they go to destroy Montag and his books. No one is safe in this society!