<P> Alison DiLaurentis is introduced as a very popular girl from the suburb of Rosewood , Pennsylvania , and the leader of a clique composed by her , Spencer Hastings , Aria Montgomery , Emily Fields and Hanna Marin . The first minutes of the pilot episode show the five friends reunited in the barn - turned - loft of the Hastings family during a night of summer vacation . In the midst of night , Hanna , Emily and Aria wake up to see Spencer arriving back to the barn after leaving to somewhere . Spencer naively announces that she has heard a scream of Alison , seemingly shaken due to something . Shortly after , Alison is pronounced as a missing person . One year later , the friends reunite and start to receive threatening text messages from someone unknown using the alias of `` A . '' During the entire first season , Alison appears in flashbacks . In these flashbacks , Alison is shown as a ruthless , despicable , two - sided teenager who uses the others ' secret against themselves . </P>
<P> Alison DiLaurentis is introduced as a very popular girl from the suburb of Rosewood , Pennsylvania , and the leader of a clique composed by her , Spencer Hastings , Aria Montgomery , Emily Fields and Hanna Marin . The first minutes of the pilot episode show the five friends reunited in the barn - turned - loft of the Hastings family during a night of summer vacation . In the midst of night , Hanna , Emily and Aria wake up to see Spencer arriving back to the barn after leaving to somewhere . Spencer naively announces that she has heard a scream of Alison , seemingly shaken due to something . Shortly after , Alison is pronounced as a missing person . One year later , the friends reunite and start to receive threatening text messages from someone unknown using the alias of `` A . '' During the entire first season , Alison appears in flashbacks . In these flashbacks , Alison is shown as a ruthless , despicable , two - sided teenager who uses the others ' secret against themselves . </P>
when does ally appear in pretty little liars
when does ally appear in pretty little liars
the pilot episode
the pilot episode