Credit: Video Still

It's hard to believe, but Pretty Little Liars has been around for four and a half seasons. That's a whole lot of mystery, drama, and even more mystery, so every week on Flashback Friday we like to look back at a memorable moment from seasons past.

Ever since the Halloween episode, we've had Alison DiLaurentis (Sasha Pieterse) on the mind, so for this week's clip, we decided to rewind all the way back to the beginning of the show to relive the first time we met Ali: In a flashback of the night she disappeared.

In this clip, the Liars, still young and naively thinking the hardest thing about high school was going to be the SATs and finding the perfect dress for the prom, are out in the barn, where they're joined by their lord and master bestie, Alison. They're giggly, drinking a little, talking about Beyonce — you know, normal high school stuff.

However, after they fall asleep, lots and lots of strange things happened, as we've since learned. When they wake back up, Aria, Hanna, and Emily are alone. Then Spencer wanders back in, dazed, saying she's looked everywhere, and can't find Ali.

Check it out yourself below.

What do you make of this scene now that you know more about what went down that night? Let us know in the comments below!

Catch the Pretty Little Liars Season 4 winter premiere on Tuesday, January 7, 2013 at 8 p.m. ET on ABC Family.

Rebecca Martin is an Associate Editor at Wetpaint Entertainment and our resident Game of Thrones, Breaking Bad, and genre TV expert. Follow her on Twitter and Google+!