In the season four premiere, the Liars are desperate to uncover what new scheme "A" has in store for them in the wake of the lodge fire, and have no choice but to turn to Mona for answers, now that she is also being targeted. Aria struggles with seeing Ezra in the wake of their breakup, and Emily starts to make plans for life after high school. Meanwhile, "A" sets Toby on a new path, what's in the trunk is revealed, and a shocking discovery reverberates through Rosewood.