Co-creator of "Chicago Fire" and developer of "Chicago P.D." Derek Haas released a few spoilers of the upcoming new seasons via Twitter.

"Chicago Fire" Season 4 premiere is titled "Let it Burn" and the title for the third season premiere of "Chicago P.D." is called "Life Is Fluid."

Haas answered a few questions for fans, revealing some spoilers for the hit NBC shows.

In the Season 3 finale of "Chicago Fire," Dawson (Monica Raymund) had taken a mystery pregnancy test. While the results were not shown, she rushed to Casey's (Jesse Spencer) to give him the news, but he was nowhere to be found. Instead, Dawson found a dead stripper at Casey's home.

Haas neither confirmed nor denied Dawson's pregnancy via Twitter. One fan asked, "Since we are all 99.9% positive Gabby is pregnant -- when in S4 will be her due date?" and Hass replied, "It takes 10 months from conception."

The same user asked if Dawson would ever get the chance to tell Casey the news about her pregnancy test. "I would keep watching through the last seconds," Haas tweeted.

He hints that Casey is still alive despite speculation that he was murdered along with the stripper. Others predicted that he was kidnapped. Will Dawson get to find out where he is? Maybe his kidnappers allowed him to make one dreadful call, and he chose Dawson.

Some of "Fire's" questions are going to be answered in "P.D." while Chicago police investigate the case.

Meanwhile, Haas spoils that someone will get into "huge, terrifying, trouble" in the Season 3 premiere. Who will it be?

"P.D.'s" Hank Voight (Jason Beghe) and Antonio Dawson (Jon Seda) are involved in Casey's twisted ending. Maybe they had something to do with him disappearing.

Showrunner Matt Olmstead previously spoiled that Dawson is angry with Antonio for what happened to Casey.

Tune into NBC in the fall to see what happens next on "Chicago Fire" and "Chicago P.D."