Sasha Pieterse Gets Slapped by Janel Parrish in This Pretty Little Liars Throwback Photo: See It Here!

Sasha Pieterse and Janel Parrish on Pretty Little Liars
Smack! Janel Parrish's Mona goes in on Sasha Pieterse's Ali in this 2014 #TBT photo from Season 5A. ABC FAMILY/Eric McCandless

In honor of #TBT (aka the glorious tradition of Throwback Thursday), Us Weekly and Pretty Little Liars have partnered to bring you the prettiest little never-before-seen photos from season one on, straight from the ABC Family drama's archives. Scroll down for more on this week's picture, and check back every Thursday to see a new one!

Slap from the past!

It's Thursday, which is always a rude awakening when you find out it's not Friday. But not as rude as a slap from Mona Vanderwaal—something Alison DiLaurentis knows all too well, as evidenced by this week's PLL #TBT photo.

For those who need a little Rosewood refresher: In season 5A's "Miss Me x 100" episode—the series' 100th—Alison (Sasha Pieterse) gets lured into the church, only to find Mona (Janel Parrish) waiting inside for a literal smackdown. Ali hit her back, and Mona records it, then uses it to turn everyone—including the Liars—against the former queen bee.

SPOILER ALERT! In today's Rosewood, Mona is dead (RIP, Mona!), and Alison is in jail, accused of killing her. (Nothing like revenge, eh?) Nevertheless, the Liars, Aria, Hanna, Spencer, and Emily, are convinced that she's still playing them, as they continue to receive threats from A, even though Ali, who they presume is their anonymous stalker, is behind bars.

Check back next week for another throwback pic—and tune in to Pretty Little Liars Tuesdays on ABC Family at 8 p.m. EST.

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