It is only four episodes away until the big "A" reveal. But for now, "Pretty Little Liars" fans have to wait and see how "A" will be finally exposed once and for all. 

Last week, Aria's brother Mike confessed something about Mona. He said that Mona tried to fake her death so she could pin it on Alison. The Liars had to tell Alison about this since they need evidence to get her out of jail. But there's one problem: she wants to tell her lawyer about Mike's revelation and Aria is begging her not to. The latter believes that this will bring more problems to her family and they can't really have that right now. 

Episode 21 is titled "Bloody Hell" and in the promo, Aria is seen talking to Alison one-on-one and asking her not to tell about Mike. On Alison's side, Mike testifying in court can help get her out of jail and clear her name. Further, it drops several hints about what will possibly happen in the episode. For one, a shot of a burn unit in the hospital is seen. What does that have to do with "A"? 

In the elevator, Hanna tells Aria, "'A' is tying up loose ends and Mike is one of them."

Is Mike in trouble now after he made the revelation? 

There's a scene where all the Liars are together and Aria asks if they are ready to rattle "A's" cage. It appears that they might actually consider telling the police what Mike told them. However, she also says, "We all know what happens when we do that," and a liar answers, "Someone ended up getting killed." 

There were two very weird scenes in the preview. First, a girl grabs a bag with blood underneath it. Later, a broken vial is seen in the bag, which is where the bloody leak is coming from. The next unusual scene is when Alison receives a message in the form of a can. When she opens it, there is a tiny doll dressed in a prison costume inside the can. 

Things are getting creepier and scarier as the episodes go by. The suspense heightens as the Liars prepare for the big "A" reveal in the season 5 finale. 

"Pretty Little Liars" will air the next episode on Feb. 24.