The fifteenth book in the #1 New York Times bestselling series that inspired the hit ABC Family TV show Pretty Little Liars. High school seniors Aria, Emily, Spencer, and Hanna barely survived their most recent encounter with A. And it's not over yet . . . The police don't believe that the real A is still out there, but the girls know what—and who—they saw. If they don't track down this final tormentor soon, A will silence them forever. Full of unexpected twists and shocking revelations, Toxic is the penultimate book in New York Times bestselling author Sara Shepard’s compelling Pretty Little Liars series.