Pretty Little Liars is like a puzzle, and we're always looking for any clue-sized piece to fill in the picture. What better source of info than the promos for each new episode? A close look often reveals potential secrets about the next week, which is why we've taken a magnifying glass to the preview of Season 4, Episode 6: "Under the Gun."

Here's what we've learned.

Spencer and Toby on a mission. Based on the episode synopsis we know Toby and Spencer follow a clue to Ravenswood, and we see shots of them in the new town throughout this promo, including some shots at what looks like a graveyard.

Hanna in trouble. Holbrook's partner, Linda Tanner, is back and ready confront Hanna. "Think about who you're trying to protect" she seems to say at :04.

Emily gets mad. At :05 we see Em looking angry in the locker room.

Mona's warning. Mona's back this week! "One wrong move, and we all go up in flames," she warns.

Aria is upset. Why does Aria look so upset at :07?

Hanna sneaking. At :08 Hanna looks like she's sneaking around.

A hidden chip. We see a makeup (or possibly paint) tray open to reveal a hidden computer chip at :08.

Hanna's worried. "Anything I do backfires!" Hanna declares.

Spencer is being watched. Someone seems to be watching Spencer through a window at :09.

A car attacks. Someone smashes a car at :10.

Aria and Ezra in the stairs. At :14 we see Aria and Ezra have an encounter in a stairwell.

Emily is "guilty." At :15 we see a video of someone in  a red coat and an Emily mask holding up a sign that says "guilty." Uh-oh. We also see someone wearing what could be an Em mask looking into a rearview mirror at :20.

Spencer needs to learn to let go. Or so Toby tells her. "Me?!" she replies. Given how obsessed he is with finding out the truth about his mom, we get her point.

Ashley is arrested. At :18 we see cops taking away Ashley Marin. "Tell her you didn't do it!" Hanna yells.

The strangest moment in Liars history. The promo promises this, while showing a shot of Spencer running, and a shot of Toby saying, "What the hell was that?!"

Watch the preview for yourself below.

Credit: YouTube Photo: Pretty Little Liars Season 4, Episode 6 Preview: Ravenswood Time! (VIDEO)

Did we miss anything important? Interpret something wrong? Share your thoughts in the comments below!

Find more Pretty Little Liars spoilers here.

Catch the next episode of Pretty Little Liars on Tuesday, July 16, 2013 at 8 p.m. ET/PT on ABC Family.

Rebecca Martin is an editor at Wetpaint Entertainment. Follow her on Twitter @BeccaDMartin.