We see some blood on a knife blade. We see blood all over a dog and then see that it's killed various other dogs, all of which are also very bloody, as are a man's hands who finds the dogs. One of these men even goes so far as to shoot and seriously wound an opponent's dog during a fight. When asked about girls, he replies that they finger them until they're eighteen. We later learn that he's also having an affair.
Some local hoods decide to sick their champion dog-fighter on any dogs they can find on the street.
Chivo turns out to be a hired assassin with a criminal past that includes killing others, putting a bomb in a mall, etc. He kills one man during this story and abducts two others. We learn that Daniel is having an affair and leaves his wife and kids for Valeria. Octavio and Susana have an affair. Octavio arranges for some men to grab and then beat Ramiro.