Credit: ABC Family

Hanna Marin is turning into quite the detective come Pretty Little Liars’ winter premiere (Season 4, Episode 14: “Who’s in the Box?”). We know the main question heading into Season 4B is who was buried in Ali’s grave, and in this new sneak peek of the episode, via E! Online, Hanna meets up with Spencer and Emily to show them what she was able to dig up.

“So I found this girl over in Cortland, named Sara Harvey,” Hanna says. “She went missing the same time Ali did. She’s blonde, same age, her parents think she ran off with a boy, and her friends set up a tribute site.”

Whoa. Nice going, Hanna! Even Spencer is impressed with Hanna’s investigative skills. Could the body in Ali’s grave be Sara Harvey? Did Ali know Sara? In order to find out, Hanna emails Sara’s friends in Cortland to set up a meeting. She tells them they have a lot in common and that they should set up a support group — we’re loving Detective Marin!

But just when the Liars seem to be figuring it all out, “A” interrupts them with a rude awakening. The race to find Ali is on, and according to “A” (or shall we say, Ezra), “whoever finds her, gets to keep her.” So not only do the girls have to figure out if Sara Harvey’s body is in Ali’s grave, they also have to keep their former bestie out of Ali’s grasp. We don’t know about you, but Season 4B sounds epic.

Watch the sneak peek from the Season 4 winter premiere over on E! Online.

Do you think Hanna is on the right track? And where is Aria hiding? Sound off in the comments!

Catch the Pretty Little Liars Season 4 winter premiere on Tuesday, January 7, 2014 at 8 p.m. ET on ABC Family.

Crystal Bell is an editor at Wetpaint Entertainment and our resident fangirl for all things Pretty Little Liars. Follow her on Twitter and Google+!