[Warning: The following contains spoilers from the series finale of Pretty Little Liars. Read at your own risk!]

A.D. has been revealed and it turns out those initials stand for Alex Drake — Spencer's (Troian Bellisario) twin sister. Yes, there is another Drake sibling and the infamous Pretty Little Liars twin twist returned for the series finale.

Eagle-eyed viewers can go back through Season 7 and try to pick out the scenes that were real Spencer and which ones were A.D. (we found one a few weeks ago), but it's going to make you feel violated to know. It turns out that Alex wanted revenge for Charlotte's (Vanessa Ray) murder because she was a member of the family she never got to have. Before Charlotte died in the clocktower, she and Alex became the best of friends. Charlotte, Archer (Huw Collins), Wren (Julian Morris) and Alex were an inseparable foursome, which made Charlotte's death that much more devastating for Alex.

Troian Bellisario and Ian Harding, <em>Pretty Little Liars</em>Troian Bellisario and Ian Harding, Pretty Little Liars

The Evil Twin became A.D. to find the truth about who killed her beloved sister and took Charlotte's money to finally have the life Spencer always had — but money wasn't enough. Alex needed the friends and the family Spencer had, so she returned to Rosewood to complete her plan.

Spencer barely had time to process she has an identical twin sister before Alex was well on her way to trying to take Spencer's place in the Liars' circle. Poor Ezra (Ian Harding) was the first to get a sense that Spencer wasn't really Spencer, and that led to him getting locked in Alex's homemade dungeon with Spencer.

It was actually Jenna Marshall (Tammin Sursok) and her blind sense of smell that figured out Alex-Spencer was a total fake. She corroborated with Toby (Keegan Allen) and he told the rest of the group, who came together (with Mona!!) to save Ezra and Spencer from the evil twin. Real Spencer was able to recite her favorite french poem for Toby and happily ever afters were free to be had — starting with Ezra and Aria's wedding.

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However, it wouldn't be PLL if everything went smoothly. It turns out Mona (Janel Parrish) is keeping Alex and Mary (Andrea Parker) as her new dolls because she could never give up the game. In a way, that's kind of the best happy ending she could ever get. The show ended with a twist by setting up a new generation of Liars, leaving fans to ask is this truly the end of their show or if they are willing to go down the rabbit hole again.

What did you think of the Pretty Little Liars series finale? Come back to TVGuide.com on Wednesday for our chat with series creator I. Marelene King and Troian Bellisario about those crazy twists.