'Pretty Little Liars' Season Finale: The 4 Most Shocking Moments

A couple reunites -- and someone has a twin. Read on...

While concocting a plan to catch the anonymous person who is blackmailing them, the Pretty Little Liars Spencer Hastings, Aria Montgomery, Hanna Marin and Emily Fields also reconnected with their former loves.

Spencer and her ex-boyfriend Toby Cavanaugh reunite while planning how to get into the hidden room in Radley Sanitarium. Spencer also tells her current boyfriend Caleb Rivers that she loves him for the first time. Her mom Veronica Hastings wins the Senate election with help from Mona Vanderwaal.

Aria and Ezra Fitz finish writing their book together, and the former couple known as "Ezria" celebrate their book being published by kissing and going to bed together.

Hanna admits to Caleb that she tried to come back to him after they broke up. After she tells him, "I never stopped loving you," the two kiss.

Emily helps Alison DiLaurentis, who is convinced she can't tell what's real anymore. She brings Alison to a hospital, where she voluntarily admits herself for psychiatric care.

But the finale also gave viewers some of the biggest reveals since we learned Charlotte DiLaurentis was "A." Check out the episode's most shocking moments below:

1. Mary Drake is Mrs. Jessica DiLaurentis' twin.

While at Radley Sanitarium, Spencer, Toby and Mona find a file on Mary Drake, who was a patient 25 years ago. Through surveillance cameras installed by Caleb, they later learn that a woman who looks like Alison's mom Mrs. DiLaurentis was the one who took Hanna. In a final scene, Mary Drake is revealed to be Mrs. DiLaurentis' twin.

2. Charlotte was not Jason's older sister.

Mary Drake's file also says she had a son named Charles Drake, who was adopted by Alison's parents. Spencer, Toby and Mona learn that Charles DiLaurentis, who went by the name Charlotte, is not actually Alison or Jason's biological sibling.

3. Dr. Elliot Rollins is working with Mary Drake.

Throughout the finale, Alison keeps seeing visions of Officer Darren Wilden and her mother back from the dead, and she becomes convinced that she need psychiatric help. But it turns out that her husband Elliot was wearing a mask to look like Officer Wilden and was working with Mary Drake all along. At the end of the episode, Elliot tells Mary that he got Alison to sign the papers, and he now owns fifty percent of the Carissimi Group, where Alison's brother Jason DiLaurentis works. "I would've done anything for Charlotte," Elliot tells Mary. "You proved that when you married her cousin," Mary says.

4. Hanna goes missing.

Ezra, Caleb and Aria discover that Hanna disappeared through a hole in the floor. The Liars later get a text thanking them for Hanna, and it's signed "A.D." The episode's final scene shows an unconscious Hanna being dragged by a mysterious figure.