** spoiler alert ** In killer, many vital clues start to unravel. such as, we figure out who killed ali. the girls figured out that it was tomas, a boy whom the girl assmed went out with ali, and was enraged that he killed her off to get rid of her. only, throughout the book, theres a new A whose giving them clues about ali's death. the girls believe that its a knock off A since many people are creating fake A's for fun. however they are not too convinced, the clues that this a gives are very suspicious and brought the girls to one solution, that thomas were sending them. except during a party, spencer gets a text from A telling her to go to the woods. when she does, the finds thomas's dead body there. when she tells the others to come, they see him there dead, and bruised. when the girls go to officer wilden back at the party, an officer whose responsible for this case they bring him to the site where they found the dead body. except, it wasnt there anymore. and no cop found his body every again. many people thought thast he ran away to some other state, and many people were conviced that the girls made up some hoax.