'Pretty Little Liars' Season 5 Spoilers, Plot Recap: Name of Big 'A' Finally Revealed

The name of Big "A" was finally revealed as "Pretty Little Liars" aired its fifth season finale on Tuesday on ABC.

Also in a major twist, Mona (Janel Parrish) returned from the dead.

At the start of the finale, all the liars – Spencer (Troian Bellisario), Hanna (Ashley Benson), Aria (Lucy Hale) and Emily (Shay Mitchell) – were on their way to prison. They have just been charged with being accessories to the murder of Mona by the convicted killer, Alison (Sasha Pieterse).

However, the four liars never got to prison as they were knocked out with gas fired from a gun held by "A" inside the bus transporting them. To their surprise, they woke up in a dollhouse.

In the dollhouse, they found Mona whose death Big "A" had faked. The liars then realized that Mona was forced to act like Alison and wore a blonde wig. They also found that "A" was watching them on cameras.

Mona then asked all the liars to go into an area without cameras. She told them she knew who she was and was just acting as Alison to appease "A."

The liars and Mona then devised a plan to escape by cutting off the electricity cable to the dollhouse. There was also a dream sequence during which Spencer finally guessed that the "A" name was Charles.

Meanwhile Toby (Keegan Allen) realized the liars were missing and contacted Spencer's parents for help. They then questioned Alison in prison and she revealed what she knew about "A." They then tried to enlist Tanner (Roma Maffia) to help them, but she was initially reluctant and instead suspected Caleb (Tyler Blackburn) of hijacking the prison van.

Tanner eventually allowed Caleb and Toby to help. They traced the prison van to Campbell farm where they found a number of monitors recording the liars' activity in the dungeon. This caused Tanner to finally believe that the girls were kidnapped.

Back at the dollhouse, the liars put their escape plan into motion while planning and participating in a prom. They employed a modified camera to blow up the source of power.

While escaping Spencer discovered a video of Alison and her younger twin brothers, and one of them was named Charles which makes her believe that "A" is Charles DiLaurentis. Finally the liars emerged from the dungeon to discover that it was surrounded by an electric fence and that they were trapped.