Pretty Little Liars seems poised to send Spencer Hastings (Troian Bellisario) down the dark path of pill addiction. Don’t believe us? Check out this sneak peek for Season 4, Episode 17 (“Bite Your Tongue”) in which Spence grills Andrew on where to get some study drugs. But how will this affect Spencer’s search for the truth about “A”? And more importantly, will it cost her Toby? We speculate on some possible outcomes.

She will quickly put the pieces together.

A focused Spencer is a dangerously productive Spencer, and we think, in the short term, she will be a force to be reckoned with. In the synopsis for Episode 17, we learn that "Spencer is working overtime to decipher the stories in Ali’s diary which she hopes will reveal the identity of Ali’s mystery man.” We think Spencer may begin to suspect Ezra, as Marlene King teased that “one of the Liars will start to suspect early on.” This all seems relatively quick, considering we just learned of Ezra’s culpability, but if Spencer basically isn’t sleeping and becomes obsessed with the quest to determine Board Short’s identity, we wouldn’t be surprised if the truth was discovered by the brainiac sooner rather than later.

Unfortunately, no one will believe her.

However, we think the speed of Spencer’s progress in uncovering information that Ezra is Board Shorts will only be equaled by the quickness of her fall. What good is learning the truth if no one believes you? We think Spencer’s storyline will turn tragic when even her friends start to doubt her killer brain and generally on-point intellect in the wake of the revelation about her drug addiction. Basically, get ready for some more stellar, heart-wrenching acting on Troian’s part.

It may cost her Toby.

Ever since learning that Keegan Allen (Toby) left Pretty Little Liars Season 4 filming early to star in an off-Broadway production, we’ve been speculating on what on-screen explanation will be given for his departure. Now, we’re wondering if it doesn’t have anything to do with Spencer’s drug-fueled obsession. It sounds like Spence is about to go high-intensity in her quest for the truth and, though Toby totally loves her, we’re not sure how long he will stick around to watch her crash and burn. At some point, we could see him using his departure as an attempt to wake Spencer up to the seriousness of her addiction. Question is: will it work?

How do you think Spencer’s pill addiction will play into her search or Board Shorts? Do you think it will be the reason for a Spoby breakup? Sound off in the comments below!

Catch the next episode of Pretty Little Liars Season 4 on Tuesday, January 28, 2013 at 8 p.m. ET on ABC Family.

Kayti Burt is a contributing writer for Wetpaint Entertainment with a penchant for all things pop culture. Follow her on Twitter and Google+!