Credit: Video Still Photo: Video: Pretty Little Liars Season 2, Episode 21 Preview: Will We See Alison's Death?

The Liars are closer to the truth than ever on Pretty Little Liars Season 2, Episode 21: “Breaking the Code.”

In this heart-stopping preview for the episode, "A" starts sending messages to Mona (Janel Parrish), and we find out the girls might actually learn the truth about Alison's (Sasha Pieterse) death. Talk about game changer.

Watch the preview here. Heck, watch it twice, or ten times — we certainly did!

Credit: YouTube Photo: Pretty Little Liars Preview: Season 2, Episode 21: ''Breaking the Code'' (VIDEO)

Be sure to tune in for the next episode of Pretty Little Liars on Monday, February 20 at 8 pm ET/PT on ABC Family.

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