The little liars miss Alison, but having her around wasn't so great either. She manipulated her best friends, threatened to tell their secrets, and criticized them for every little flaw. Ali messed with all four girls, but her relationship with Spencer was especially competitive and destructive.
In tonight’s episode, “If At First You Don’t Succeed, Lie, Lie, Again,” we’ll see a flashback of Ali and Spencer having a huge fight the night Ali died. Alison demands that Spencer tell Melissa about her kiss with Ian and Spencer tells Alison that she's sick of her games.
Alison promises that Melissa will know about Spencer and Ian by the morning, but since Ali didn't make it to the next day, does it mean Spencer had something to do with her death?