We haven’t seen a Pretty Little Liars flashback to the night of Ali’s disappearance for awhile, but it looks like that is about to change. Check out the tweet Troian Bellisario (Spencer Hastings) just shared about an upcoming glimpse into the past.

“Uh oh. Haven't seen this sweater in 4 years... Wonder what we are shooting tonight? #pll. PS. i still hate this outfit just as much as I used to,” Troian intriguingly (and hilariously) tweeted yesterday, along with a pic of the jeans, white button-up, and argyle sweater aka the outfit Spencer was wearing the night Ali was allegedly killed. Looks like we’re in store for another flashback!

Credit: Instagram

In addition to the PLL pilot, we saw Spencer wearing that outfit in a flashback in Season 1, Episode 15: “If At First You Don’t Succeed, Lie, Lie Again.” The flashback shows Spencer fighting with Ali that night. Ali coerces Spencer into telling Melissa that she kissed Ian (Melissa’s then boyfriend) by saying that, if Spence didn’t ‘fess up to her big sister, then Ali would tell Melissa herself… the next day. Spencer agrees to come clean, but tells Ali that things are going to change between them. “I am sick of your games. We all are … As far as I’m concerned, you are dead to me already.” Ouch.

Will the upcoming flashback reveal more of what happened after that conversation, or will it be set earlier in the day? Spencer claimed that, even though she went after Ali, that conversation was the last she saw of her friend. Was she telling the truth? Or is there more to their story...?

Are you as excited for this flashback as we are? And what do you think of Spencer’s argyle sweater? Sound off in the comments below!

Catch the Pretty Little Liars Season 4 Halloween special on Tuesday, October 22, 2013 at 8 p.m. ET on ABC Family.

Credit: Celebified Photo: Pretty Little Liars Halloween Special "grave New World" Preview Photos: Ezra Lurks In The Shadows While The Girls Search For Ali!