The Insider.com

Pretty Little Liars kicked it old school in last night's one-off Halloween special, titled The First Secret -- but that should have definitely been pluralized as fans learned a helluva lot about all the characters. But nowhere did the revealtions come faster, or in greater numbers, than with dearly (un)departed Alison DiLaurentis. Actress Sasha Pieterse, who plays the original PLL, told Insider.com that the entire episode was filled with subtle clues to the show's on-going mysteries. Particularly in Alison's room! Let's dig in!