More uncertain than ever, Cadence reluctantly joins Harris on an excursion, triggering memories of their final confrontation in Summer 16. During a tense family dinner, The Liars confront their mothers about family secrets. In the aftermath of shocking revelations, The Liars mourn their once-beloved childhood playground and unite in an attempt to save their fracturing family.

Cadence devises a plan to trigger her latent memories of the final hours before her traumatic accident, but she can't do it alone – she must convince the reluctant Johnny, Mirren, and Gat to help her, even if it means risking everything. But as the truth begins to come back to her in fits and starts, Cadence realizes that she, herself, has been the biggest Liar of all.