Who is “A” and why have they been targeting the girls on “Pretty Little Liars”? Fans of the ABC Family drama are going to find out on Tuesday. The series is following through on their “Summer of Answers” tease by revealing answers to some of the questions that have been haunting viewers for years.

The big reveal is going to go down during the Season 6 summer finale tomorrow evening. But the show has actually been dropping hints all season. The nine episodes leading up to the finale have all included some sort of clue or bombshell about Charles DiLaurentis/ “A,” and we’ve rounded up everything we learned about the masked tormentor so far:

Season 6, episode 1

The Season 6 premiere exposes Charles’ secret vault at the dollhouse. The room is where he kept some of his most prized belongings – including the childhood video footage of Mrs. DiLaurentis (Andrea Parker) with Jason (Drew Van Acker), Alison (Sasha Pieterse) and Charles. It’s during episode 1 that viewers also learn that Charles had kidnapped Sara Harvey (Dre Davis) years ago. What fans still don’t know though is why Charles kept her locked up … and dressed like Alison.

Season 6, episode 2

In episode 2 Sara tells Emily (Shay Mitchell) that all she remembers from her kidnapping is that she ran away from home and was hanging out in a parking lot near Rosewood when she was struck on the head. She later woke up in Charles’ Dollhouse.

Season 6, episode 3

Although Mr. DiLaurentis (Jim Abele) denied knowing a relative named Charles, Jason confesses to Spencer (Troian Bellisario) that he does remember someone named Charlie from his childhood. The catch is that Jason believes that Charlie was his imaginary friend. He reveals to Spencer that his dad told him that Charlie had to “go away” one day … and he never saw him again.

Episode 3 is also when the girls find Mrs. DiLaurentis’ hidden photo of Charles with his siblings. Armed with proof that Charles really did – or does – exist, Alison brings the photo to her dad to demand to know who the boy is.

Season 6, episode 4

Mr. DiLaurentis finally comes clean about Charles to Alison and Jason in episode 4. He reveals that Charles is 15 months older than Jason and that he was “trouble” at an early age. But Charles wasn’t just a problem child – he was dangerous. According to Mr. DiLaurentis, they had to institutionalize him at Radley shortly after Alison turned one. The reason? He tried to drown Alison in scalding hot bathwater.  At the time the family wasn’t living in Rosewood, but moved to the town to be closer to Charles.

But that’s not the only bombshell that Mr. DiLaurentis drops – he claims that Charles committed suicide by overdosing on pills when he was 16 years old. The body was allegedly cremated.

Not trusting Alison’s father, the Liars do some more digging. They break into a shredding center and find that two people frequently visited Charles – Mrs. DiLaurentis and Alison’s great aunt, Carol Ward. Unfortunately Aunt Carol can’t shed any light on Charles because she died when they were in 10th grade. But clues do remain at Aunt Carol’s house. Jason tells his sister about a strange experience he had with their mother when he tried to stay at Carol’s home following his accident in the elevator. Mrs. DiLaurentis refused, claiming that there was no water in the house. However, Jason believes that she was hiding someone there – potentially Charles.

Armed with this new theory, Alison and Jason go to Carol’s house with Hanna (Ashley Benson) and Spencer (Troian Bellisario). Although they don’t find anyone in the house, they do find a grave belonging to Charles. The discovery leads them to believe that Charles is really dead, but that someone he knew from Radley stole his identity.

pretty-little-liars Alison (Sasha Pieterse) and Jason (Drew Van Acker) discovered Charles' grave in episode 4 of "Pretty Little Liars." Photo: ABC Family

Season 6, episode 5

Aria’s (Lucy Hale) photography friend Clark (Titus Makin Jr.) accidentally ends up taking a photo of “A” in episode 5 while they’re at a junk yard shooting. A closer look at “A’s” figure reveals that their tormentor might actually be a girl.

The theory that “A” might be a girl leads the Liars to eye a new suspect – Mona’s (Janel Parrish) friend, Lesli (Elizabeth McLaughlin). It turns out that Lesli was at Radley the same time as Mona, Charles AND Bethany Young, the dead girl that was mistaken for Alison. In fact, Lesli was Bethany’s roommate. When the Liars find proof that Charles’ organs were donated after his death, they become pretty certain that Lesli has been behind all their troubles over the years.

Season 6, episode 6

Although paperwork claims that Charles is dead, Mona reveals in episode 6 that the documents are a sham. According to Lesli, Charles escaped Radley the same night that Alison was “killed.” With Lesli’s name cleared, that means Charles is truly on the loose … and he leaves a loving note for his dad:

“Dead Daddy, Coming home for my birthday. You should plan a party to die for. Just you. Love, Charles.”

Season 6, episode 7

Mr. DiLaurentis dug up Charles’ grave at Carol’s house and presumably discovered no body because episode 7 starts with him taking Alison out of Rosewood. Charles ends up leaving another note at the DiLaurentis house – an invitation that says “come alone or not at all.”

Although Mr. DiLaurentis is too afraid to come face-to-face with his estranged son, Jason decides to follow through and meet Charles at an abandoned arcade. He’s about to meet his brother when Toby (Keegan Allen) and Lorenzo (Travis Winfrey) crash the party and ruin the whole plan.

Charles escapes, but returns to the DiLaurentis house. He leaves Jason and Alison a home video in the attic. The two discover that the footage is from a “second cousin’s birthday party. What they didn’t realize at the time was that the kid they were playing with, Freddy, was actually their brother Charles. Charles leaves a note with the movie – “I wAnted to trust you.”

Another big reveal in episode 7 is that Charles has an accomplice. He gets a birthday gift from a “friend and ally.”

Pretty Little Liars Toby (Keegan Allen) and Lorenzo (Travis Winfrey) failed to catch Charles in episode 7 of "Pretty Little Liars." Photo: ABC Family

Season 6, episode 8

The DiLaurentis family is somehow connected to the Carissimi Group, the mysterious organization that granted Hanna with a $30,000 scholarship. Hanna doesn’t want to accept the money, but her mom’s not taking no for an answer. As a piece offering she tries to contact Mr. DiLaurentis to ask him about the group, but he doesn’t answer her calls. Hanna decides to take matters into her own hands in episode 8 and goes to the Carissimi Group building with Spencer. They wait in an office for a man named Rhys Matthews (Caleb Lane), and they’re surprised by who finally enters the room – a man who looks eerily like Jason DiLaurentis.

Hanna declines the tuition money and returns it to Rhys. She asks about his employer, but Rhys reveals that Mr. Carissimi wants to remain anonymous.

Hanna and Spencer leave but they have more questions than ever. Fortunately they run into Rhys again. They spot him in a car outside Aria’s photography exhibit. When the girls follow him they end up at an abandoned doll factory. But surprisingly they’re not alone. Clark meets Rhys inside.

Meanwhile, it’s revealed that Charles is working with Red Coat on torturing the girls. The two villains are seen working together to ruin Aria’s photography exhibit.

Season 6, episode 9

It’s revealed in episode 9 that Clark is actually an undercover police officer. So, what was he doing meeting up with Rhys Matthews in the previous episode? That’s hopefully a question that will be answered during the summer finale.

Speaking of Rhys, he shows up at the DiLaurentis house looking for Kenneth. But Mr. DiLaurentis is nowhere to be found. Instead, Rhys runs into Veronica Hastings (Lesley Fera), Pam Fields (Nia Peeples), Ashley Marin (Laura Leighton) and Ella Montgomery (Holly Marie Combs). The moms quickly put two and two together that Rhys looks like Jason, and that he could potentially be Charles DiLaurentis. Rhys leaves the house, and the women end up getting locked in the DiLaurentis basement when they hear a noise come from downstairs.

The big jaw dropper comes when Charles finally confronts Alison at prom. He covers her mouth and takes her out of the room. But before he completely removes her from the building, Charles unveils his face. Alison’s final words are, “Oh, my god.”

The “Pretty Little Liars” Season 6 summer finale airs on ABC Family on Tuesday, Aug. 11 at 8 p.m. EDT. What do you think about all the Charles DiLaurentis/ “A” clues? Tweet your thoughts to @AmandaTVScoop.

Pretty Little Liars Aria (Lucy Hale), Spencer (Troian Bellisario), Mona (Janel Parrish), Emily (Shay Mitchell) and Hanna (Ashley Benson) will finally come face-to-face with their tormentor in the Season 6 summer finale of "Pretty Little Liars." Photo: ABC Family