We were all in shock when at the end of season two finale of Pretty Little Liars, we finally discovered the identity of A, who had been tormenting Hanna (Ashley Benson), Spencer (Troian Bellasario), Aria (Lucy Hale) and Emily (Shay Mitchell).
It was Mona (Janel Parrish), which hit Hanna the hardest, as she was Mona's best friend. How could Mona have been the one torturing them all this time?
But was Mona really the only 'A'? When the premiere picks up tonight, Hanna returns to Rosewood after spending the summer apart from everyone and decides that she has to go visit Mona in the mental hospital to get some answers. But those won't be so easy to come by.
Check out the sneak peek below from tonight's episode. And don't miss the season premiere of Pretty Little Liars tonight at 8 p.m. ET on ABC Family!