Aria Emily Spencer Hanna & Alison have been best friends since the third grade They go everywhere together thinking no-one can come between them If anyone is the ringleader of the group it is Alison & the other girls cannot help but confide all their secrets to her One night during a sleepover Alison goes missing Her body is never found The girls mourn her death but move apart after time assuming their secrets have disappeared with Alison too Three years later & Aria is having an affair with her teacher; Emily is questioning her sexuality; Hanna is a thief; & Spencer is flirting with her sister's fiance They all think their secrets are safe until they starting receiving messages from the mysterious A
- who knows exactly what they are all up to & is threatening to spill the beans