Pretty Little Liars

The short version:

The book ends in a cliffhanger when the house explodes and Ali's body is not found.

The long version:

Alison has a twin sister named Courtney. Courtney has a history of pretending to be Ali since she has a mental issue, and she stays at a hospital which is why we never hear of Courtney. So one day (the day the girls try to steal Ali's flag), Courtney is home because she is switching hospitals, and Ali is up in her room. Courtney comes and befriends Aria, Spencer, Emily and Hanna while Alison is in the house. Mrs. Dilaurentis mistakes Ali for Courtney and takes her to the hospital. When Ali tries to tell her mom she is Ali, her mom thinks it's just Courtney pretending to be Ali again. So, Ali then spends some time in the preserve that Hanna stays at in the series which is how Iris knows Ali who she thinks is Courtney. So, this whole time Courtney is friends with the 4 girls who they think is Alison but it's not.

Then at their sleepover, Courtney who is really Ali comes back from the hospital for summer. She is jealous of Courtney's life and how Courtney took it from her. Meanwhile, Courtney (as Ali) is with the girls having their 7th grade sleepover. When Courtney (as Ali) tries to hypnotize them, Spencer gets mad and orders Courtney (as Ali) to get out. Courtney goes outside to meet up with Ian after that, but in the act, Alison (as Courtney) takes her and pushes her in the hole, killing her. Btw, Alison was the one who was stalking them in the window during the sleepover.

Then, when Courtney (who everyone thought was Ali) doesn't return, the family and her friends thinks Alison is missing, but really the REAL Alison who was never friends with the 4 girls as they thought, is still at the preserve. Then in Wanted, Alison (as Courtney) returns and the girls believe all her lies as she tells them she is Alison (who they never really knew...they knew Courtney). Then Alison tells her story acting as if she was their best friend.

On their trip with Alison (acting as their old best friend who was Courtney but they thought she was Alison), Ali tries to kill the 4 girls because she is mad Courtney chose them as her bffs (they were losers). The real Alison also killed Jenna and Ian because she was afraid they would spill her secret. Ali is also the new A and she got all of their secrets just like Mona did, from Courtney (acting as Ali)'s journal.

So... really the girls never knew Ali. They knew her twin, Courtney who they thought was Ali, but Courtney (as Ali) died and the real Alison killed her. Really, just think of Ali as Courtney and Courtney as Ali.

Ok well when the girls find out that A is Mona and Mona's gone the girls think everything will go back to normal. WRONG! A comes back and this time A is Alison. You see Alison never died. It was her twin sister Courtney that died. When the girl met Ali that summer it wasn't Alison. It was her twin sister Courtney pretending to be her while Ali was taking her place at Courtney's mental hospital. So Ali comes back as A. Then Ali gets them all to come to her summer house and locks them in a closet. The girls find that Melissa and Ian were there to. Ian was dead. Ali then send them a text message saying the the Ali they knew was Courtney. The girls find a secret passage and find Ali about to escape but Emily pulls her back in they escape with Ali back inside. That's when the house explodes. The girls tell the police EVERYTHING but when the fireman go to the house they only find Ian's body. Alison's body is no where to be found.

this is hard to answer and A HUGE SPOILER!

Ali had a twin named Courtney! Courtney had a mental disorder and was put in the hospital for life. Somehow she escaped and managed to pretend to be Ali and convinced their mom she was Ali. So the real Ali was sent back to the hospital and lived a terrible year. Courtney became friends with the four girls and stated their clique. So .One day alli came back and killed Courtney ( who everyone thought was ali ) Although in the end, Ali trys to kill all the girls and almost suceeds but ends up killing herself ( or that's what they think). The last page in the book hints that she is still alive. Yepppp prettty confusing
Ali* "died" in the fire at her house. Her twin, Courtney, was murdered by Ali by getting thrown into a hole in their yard that was there for their gazebo

The first para in Pretty Little Liars the first book (the prologue) is

Sure, Alison was Alison. She was the solder to cry on, the only one you'd ever want calling up your crush to see how he felt about you, and the final word on whether your new jeans make your butt look big. But the girls were also afraid of her. Ali new more about them then anyone else did, including the bad stuff they wanted to bury-just like a body. It was horrible to think Ali might be dead, but . . . if she was, at least their secrets were safe. At least, for three years, anyway.

The first para of the actual story is

"Someone finally bought the DiLaurentise's old house" Emily Fields's mother said. It was Saturday afternoon and Mrs. Fields sat at the kitchen table, bifocals perched on her nose, calmly doing her bills. Emily felt the Vanilla Coke she was drinking fizz up her nose.

Hope this helps ^_^

(Alison never really died it was her twin sister)
Mona, Allison, Melissa,

Tammin Sursok. She's an Australian actress. She was on the soap operas Home and Away and The Young and the Restless. She was also in the films Aquamarine, Spectacular, and Flicka 2.

Now portrays the role of sienna in Hannah Montana forever.