The hound sniffed out Montag. Once the hound was given Montag's DNA he was on a hunt to kill him. Montag ends up hiding in a river so the hound cannot smell him.
When the mechanical hound was chasing Montag he went to Faber's house. Faber didn't want the hound to come to his house so he tried to hide any trace of Montag being there. He also gave Montag some of his oldest and smelliest clothes to try and cover up the smell of Montag.
Montag was being hunted down by the mechanical hound. He ended up hiding in a river so the hound could not smell him. The water ended up saving his life.
People no longer have to think. They have all information handed to them. Mildred is an example of a zombie because she lives for her parlor and pills. That's all she needs.