Toxic is the fifteenth—and second-to-last—volume in Sara Shepard's #1 New York Times bestselling Pretty Little Liars series, also a hit ABC Family original TV show.

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.

This penultimate installment of the beloved series is full of juicy scandals, dark secrets, and shocking plot twists that will prepare readers for the jaw-dropping series conclusion in Pretty Little Liars #16.