On Pretty Little Liars Season 4, Episode 21 ("She's Come Undone") Aria got a look at Ezra's notebook, which appears to be an extensive account of everything he discovered about the Liars and Ali over the years. And those notes tell us a lot about what was going through Ezra's head as he pursued his investigation while dating Aria.

We'd already seen a few of his notes in the sneak peek, but more was revealed in the episode itself. So let's go over what we saw in his journal while Aria flipped through it.

First, Ezra's opening thoughts:

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It all started on a day just like any other day in the small town of Rosewood. A small town and a small community like so many other small towns in the U.S. Everybody's into everybody else's business. Families intertwined, not by blood but by secrets.

Secrets in a small town can be Destructive. Explosive. Precursors to more secrets, more lies, more destruction, and more explosions. The day Alison DiLaurentis went missing changed the small town of Rosewood and everyone who lives here. One by one. Family and friends. Taking a look into the lives of Alison's family and friends may help trying to uncover what happened to Alison.

This doesn't give us any new info, but it does explain why Ezra dug so far into the Liars' lives in the first place: he thought they would provide clues about what happened to Ali.

And now, his "initial impressions" of Aria:

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Beginning with the Initial Impressions of the four main friends:

(all striving to be just as popular as Alison.)

Aria Montgomery is an independent girl

(Considered to be the oddball of the group in Rosewood.)

Artistic/bubbly/independent

3 years spent in Iceland with her family

feels out of place in Rosewood & tends to be attracted to older (more worldly men)

Struggles to keep family matters from affecting her schoolwork.

Family struggles? Dad cheating?

Possibly carrying on multiple relationships @ one time?

Goes to local art galleries/art shows & openings

--> Get to know favorite artists

Yeah. This list? Is disturbing to us. He explicitly thought she was into older men, and made a note to learn about her favorite artists. The beginning of their relationship is looking faker and faker. (Also, he says she was in Iceland for three years. We thought it was only one? Is he way off? What's going on with that? Seems like a pretty basic fact.)

Here's what he has to say about the night of Ali's disappearance:

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Five BFF's have a party night at the barn. Talking. Drinking. Sharing secrets --> that's what keeps best friends close.

Fell asleep. Woke up. No Alison.

Searched the property.

Still no Alison.

Report the disappearance.

Investigation leads nowhere.

Newspaper reports - "Still missing"

A few years go by - Group splits up/goes different directions.

OK, two thoughts on this section: First, how does he know Ali said secrets are what keep friends close? Did she tell him that once, too? Second, why does he say "a few years" went by? One year went by between Ali's death and the start of the series, when the Liars became friends again.

Next section. Ezra talks about starting to fall for Aria:

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Aria continues to be a wealth of information. My only concern is that I am falling for her and the line between morality and investigative curiosity becoming increasingly blurred. However, the insight into Aria's relationship with Alison sheds expansive light as to the possible suspect motives.

Today Aria told me she caught her dad having an affair with a student last year.

Alison knew about the affair too.

As mentioned previously, that could play into Alison DiLaurentis's death. The rich context of the how's & why's become clearer as Aria explains the relationship she had with Aria.

So. So. Ezra was still taking notes even as he was falling for Aria. He knew it was the wrong thing to do and still kept it up. Though if you ask us, the "line between morality and investigative curiosity" was crossed as soon as he knowingly hooked up with a teen girl. But that's just us. (Actually, no, it's not. That's the law.)

Finally, more proof that Ezra was still investigating well into his relationship with Aria:

And no new information attained to this point. But — I have a meeting set up later tonight w/Aria...

Aria and her friends blinded Jenna in a prank gone wrong.

Alison was the instigator.

Possible motive for her murder: Someone seeking Revenge. But Who? A boyfriend? Toby?

Man… it really does seem like Ezra knew everything. We don't know about you guys, but we find that seriously twisted.

What do you make of Ezra's notes? Let us know in the comments below!

Catch the next episode of Pretty Little Liars on Tuesday, March 4, 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+!