When "Pretty Little Liars" returns for its next season, it will be without one important character.

The summer finale for the show aired on Tuesday, and in the episode, the four main characters are afraid of what Alison may do to them, so they try to get help from Mona.

The Liars learn, through hacking through the police database, that Alison didn't turn them in, but she did say enough to tie the girls to more problems. Specifically, police believed that Spencer might have had something to do with Bethany Young's death.

As always, the Liars have a plan. Spencer and Mona dress up as nurses and break into Radley to get Bethany's files. The whole team helps, with Aria distracting personnel during her shift, Caleb and Hanna use computer software to get them inside and Emily gets Alison to come to her house.

Spencer and Mona do get the files, which showed that Bethany's father and Alison's mother had an affair, but Holbrook comes to Radley to talk to Aria about Spencer.

On Thanksgiving, Paige tells the Liars that Alison, Mindy and Cindy joined up with many other people, and the girls realize that Alison will be coming back strong, with her own group.

Mona found out that Alison knew about her mother's affair, and that she ended up killing Bethany. Mona tried to call Aria to tell her, but she is being watched.

A hoodie wearing blonde murders Mona.

Holbrook tells reporters that they have ruled Mona's death a homicide. He also says that her body wasn't found, but the amount of blood indicated that she was dead.

On "Pretty Little Liars," however, dead doesn't always mean gone. Janel Parrish, who plays Mona, has confirmed that her character is dead, but she's not completely out of Rosewood.