Stana Katic Stana Katic

Beckett will finally be forced to face her PTSD head-on in Monday's episode of Castle.

When a sniper begins taking out New York City citizens at random, Beckett (Stana Katic) will begin to relive her own experience of being shot by a sniper in the Season 3 finale. As the case heats up, she'll become more unstable, forcing her to confront her "lost" memories after the shooting.

Castle Boss: Castle and Beckett's new secrets are a "ticking bomb"

Check out this first look at Monday's episode to find out just how far down the rabbit hole Beckett will go:

Castle airs Mondays at 10/9c on ABC.