'Pretty Little Liars' Season 5 Finale: Online Streaming Information; 5 Episodes that Contain Clues to A's Identity

Season 5 of "Pretty Little Liars" is coming to a conclusion with "Welcome to the Dollhouse," the episode that will give viewers the biggest clue to the A mystery.

The finale will air live on Tuesday at 8 p.m. ET, and it can be viewed online through ABCFamily.com. But before the episode airs, here are five important episodes to re-watch that contain major clues to A's identity.

E!Online caught up with "Pretty Little Liars" showrunner Marlene King before the finale airs, and according to her, the following episodes are a must-watch.

• "It Happened 'That Night,'" season three, episode 1
• "A Dangerous Game," season three, episode 24
• "A Is for Answers," season four, episode 24
• "Taking This One to the Grave," season five, episode 12
• "How the 'A' Stole Christmas," season five, episode 13

The finale is expected to have a lot of shocking moments, and one of them is expected to be regarding the whereabouts of Mona, who was presumed dead. Reportedly, the character will be shown as alive, and in A's captivity, towards the end of the episode.

Talking about the big A reveal, Sasha Pieterse, who essays Alison in the teen drama, told People that the finale will be dark and twisted.

"It's not something that you would expect or even that the viewers would be like, 'Oh, that makes sense,'" Pieterse said of the #BigAReveal in the Pretty Little Liars Season 5 finale. "It's actually very dark, especially for this kind of TV show. I enjoy it, and I think it's got great places to go, and I know the writers are having a ball continuing writing for the sixth season and planning for the seventh season. We're very lucky, and I think the fans, it's literally going to blow their minds."

But the biggest shock will come when Big "A" is unmasked, said Pieterse, adding that it's more disheartening and sad than shocking.