: Spencer experiences "pieces" of her own past through dark flashbacks of the dollhouse, where she remembers being covered in blood.
In the Pretty Little Liars episode (Season 6, Episode 4), the "pieces" refer to the missing evidence of Charles DiLaurentis' past . [S6E4] Don't Look Now
After Kenneth DiLaurentis confesses that Charles was Jason's older brother who was sent to Radley Sanitarium as a child, the girls realize they must find proof of his history—or his death—before it is erased. Key "pieces" of the mystery in this episode include: : Spencer experiences "pieces" of her own past