"Chicago Fire" will return for a fourth season to reveal the truth about Casey.

In the Season 3 finale, Casey went missing while his stripper friend was found dead on the floor, CaterMatt reports. Shockingly, Dawson discovered this bad news while on her way to reveal her pregnancy test results to Casey. Is she expecting?

The show's executive producer Matt Olmstead reveals a new theme for Season 4 to The Hollywood Reporter.

"There are shifts within the firehouse that you're going to see ... in terms of personnel and people having some new roles within the firehouse -- within their personal lives," he said. "People get knocked out of their comfort zone a little bit and we see how they react to it."

There will also be an introduction of new characters.

"We're excited about bringing in a new candidate to the firehouse, which we're going to cast and look for," Olmstead revealed.

"It's another opportunity to bring in new blood with the graduation of characters and the Mills character going off," he added. "It opens up a spot for a new character -- a new candidate -- and we're tossing around ideas right now about who that character will be."

"Chicago Fire" will return to NBC in November to answer a lot of questions that the season finale left, CaterMatt notes.

Fans are excited to see how the story line unfolds. There is high expectation that Dawson is pregnant because she rushed over to Casey to tell him the news.

If she is pregnant, then it means a lot will change for her professionally and personally. The biggest issue is that she cannot be a firefighter while pregnant. Will she be switched to desk work or actually leave the show?

But the most anticipated news is to find out what really happened to Casey. Is he going to be a father? If so, will the case with the dead stripper affect his parental duties?

Check NBC in the fall for the premiere of "Chicago Fire" Season 4.