Pretty Little Liars season 4, episode 21 “She’s Come Undone” airs tonight at 8 p.m ET on ABC Family! Catch up on all the stills and this week’s promo to get you ready for the new episode.

Last week on Pretty Little Liars we were all gearing up find out that Ezra (Ian Harding) was A, but writers duped us all again. Aria’s (Lucy Hale) boyfriend revealed that he not only used to date Ali (Sasha Pieterse) in college but his reason for coming to Rosewood was to do a bit of investigative reporting for the true crime book he was writing about her. The Liars also found themselves confronting Spencer (Troian Bellisario), who seemed to be spiralling out of control very fast, about her drug problem.

Stills for ‘Pretty Little Liars’ season 4, episode 21 ‘She’s Come Undone’ show Aria trashing Ezra’s apartment :

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The synopsis for ‘Pretty Little Liars’ season 4, episode 21 ‘She’s Come Undone’ is:

“Aria grapples with Ezra’s betrayal while Spencer must deal with the fallout from her addiction. Emily, Hanna and Spencer are concerned for Aria as they watch their friend crumble after learning shocking news about Ezra. Not knowing what is true or what to trust, Aria goes looking for answers, not wanting to believe this revelation to be true. While concerned for Aria, Spencer is not doing so well herself. Trying to prove to her parents and Toby that she can kick the habit on her own, Spencer has to be careful because one misstep could send her to rehab. But can Spencer really rein it in, or will her constant curiosity and drive be her undoing? Meanwhile, Paige has had enough with Emily’s secrets and is determined to stop it.”

Watch a preview from the episode below:

Where to watch ‘Pretty Little Liars’ season 4, episode 21 ‘She’s Come Undone’ online:

If you cannot watch Pretty Little Liars live, ABC Family will put the episode on Hulu the next morning or you can set your DVR and watch it whenever you like. As always, try and avoid Twitter if you don’t want to risk getting spoiled.

Will you be watching ‘Pretty Little Liars’ live tonight?

Photo credit: ABC Family