This Thursday marks a major episode in the mythology of Fringe.

The show's final installment until mid-March, "Jacksonville" focuses on the sole survivor of an earthquake-destroyed building in Manhattan.

When this individual turns out to be from an alternate universe, Walter leads the unit to Jacksonville, Florida, the site of a relevant experiment he and William Bell conduced a long time ago.

What will prevent another catastrophe? Olivia and the secrets of her past.

Click on the pictures below for an early look at scenes from "Jacksonville," as it reveals more than ever about Agent Dunham...

For more on what will go down this spring, visit our section of Fringe spoilers.

Below, we've posted the official Fox trailer for this episode. Check it out now.

[video url="http://www.tvfanatic.com/videos/jacksonville-promo/" title="Jacksonville Promo"] [/video]

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.