<P> Eventually , Alison is linked to an old doll hospital in town nearby called Brookhaven , and later a rural motel , The Lost Woods Resort . The girls attend a masquerade party , where they plan to confront `` - A '' who appears to be a woman dressed as The Black Swan from Swan Lake . Spencer , accompanied by Mona , rides out to Lost Woods , while the other girls chase `` - A '' . Spencer and Mona are able to steal the key to one of the rooms , which is revealed to be `` - A 's '' Lair . Mona then reveals to Spencer that she is `` - A '' , while the woman at the costume party was only a decoy . Mona knocks Spencer unconscious , driving her to a nearby cliff . She gives Spencer the option of joining her `` - A '' Team , or dying . </P>
<P> Eventually , Alison is linked to an old doll hospital in town nearby called Brookhaven , and later a rural motel , The Lost Woods Resort . The girls attend a masquerade party , where they plan to confront `` - A '' who appears to be a woman dressed as The Black Swan from Swan Lake . Spencer , accompanied by Mona , rides out to Lost Woods , while the other girls chase `` - A '' . Spencer and Mona are able to steal the key to one of the rooms , which is revealed to be `` - A 's '' Lair . Mona then reveals to Spencer that she is `` - A '' , while the woman at the costume party was only a decoy . Mona knocks Spencer unconscious , driving her to a nearby cliff . She gives Spencer the option of joining her `` - A '' Team , or dying . </P>
who is a in season 2 of pll
who is a in season 2 of pll
Mona
Mona