Credit: ABC FAMILY/Eric McCandless

Pretty Little Liars Season 5, Episode 5 (“Miss Me x 100") is the 100th episode of the beloved teen murder mystery, and that means the writers went all out to bring us a dramatic, engaging episode worthy of such an important milestone. Based on the promo for the episode, it's not going to disappoint.

What can we expect from this huge episode? We've taken a close look at the preview to find out exactly what we can learn from it.


1. Ali is back! Alison (Sasha Pieterse) is back in school this week — and as we see in the opening shot of the promo, she's going to enter with the Liars by her side. Whatever hesitation our girls might feel about their un-dead friend, of course they won't let her face Mona (Janel Parrish) and her army alone. For proof of that, look no further than Spencer telling Mona they aren't afraid of her at :09.

2. "What she's been through changed her." "She says that what she's been through changed her," someone (Spencer [Troian Bellisario]? It's hard to tell) says in voiceover at :02. We're supposed to assume that sentence is about Ali, but we're not sure. Could it be about Jenna (Tammin Sursok)? We know she's back this week, too...

3. Who wants to punish the Liars? "She's back to punish us for it!" Hanna (Ashley Benson) worries at :06. That we're pretty sure is about Jenna. After all, we don't think the Liars would be very worried about Ali "punishing" them, and it makes sense that they would think that Jenna is out to get them because of Shana's (Aeriel Miranda) death.

4. Aria and Emily seem upset. What is Aria (Lucy Hale) so shocked about at :07? It looks like she's seen something unexpected. And what about the next shot, which shows Emily (Shay Mitchell) looking sad, or maybe even guilty? We want to know more!

5. Ali out at night. At :08 we see Ali out at night, and at :11 we see her walking alone, and then she seems to be followed by someone at :12. We're not sure these are the same scene — at :08 she's wearing a beige coat that is nowhere to be seen at :11 — but whatever the case, we're always worried when one of the girls wanders Rosewood in the dark.

6. The Liars also out at night. Speaking of, at :13 we see Aria and Spencer also walking around at night. Are they meeting Ali?

7. Spencer wants to know the truth! "I just want to know the truth!" Spencer yells at someone who looks, from the back, like her mom. We know you want the truth, Spence, but getting it from your family might be a lost cause.

8. Ali vs. Mona. We're thinking the person who follows Ali at :11 is Mona, because at :16 we see that they have a major confrontation, and Ali is wearing the same outfit from the outdoor scene. Either way, we just can't wait for this showdown. The claws are coming out — Mona even slaps Ali!

Check it out yourself here.

Did we miss something? Interpret something wrong? Share your observations in the comments below!

Catch the next episode of Pretty Little Liars on July 8, 2014 at 8 p.m. ET on ABC.

Rebecca Martin is an Associate Editor at Wetpaint Entertainment and our resident Game of Thrones, Breaking Bad, and genre TV expert. Follow her on Twitter and Google+!