Dr. Daniel Charles of "Chicago Med"  will be appearing in an episode of "Chicago Fire" Season 4 to assist Brett and Chili in their tedious and emotionally draining first call in the season premiere. Meanwhile, Casey does undercover work in a strip club.

Christian Post confirmed that Dr. Charles (Oliver Platt) will also be appearing in "Chicago PD" to promote the spinoff series, "Chicago Med". The report says that fans can expect a four-way crossover between "Chicago Fire," "Chicago P.D.," "Chicago Med" and "Law & Order: SVU" in the upcoming season.

"Chicago Fire" Season 4 will reveal the truth about Matt Casey reports  Design n Trend. Season 3 ended with his disappearance after his stripper friend was found dead in his apartment. Gabby Dawson was about to tell him about the pregnancy test results when she learned that Casey was missing. It was not revealed if she was indeed pregnant.

If she is pregnant, she can no longer be a firefighter which she fought long and hard to become. The only alternative will be a desk job in the firehouse. In the upcoming season, Dawson will seek the help of Chicago PD's Voight and Antonio. They will lead the search for Casey.

The season premiere titled "Let It Burn" will feature Casey in a very serious situation when he goes undercover to bring down Jack Nesbitt's strip club reports  Cartermatt. Somebody will be seriously injured in a shootout but who that person is will not yet be revealed. Although Casey will survive the incident, the ordeal will haunt him for the rest of the season.

Meanwhile, Severide will get a rude awakening because of the high turnover of the squad. His management skills will be questioned and he will be forced to go on a management training program after his demotion. It is there however that he meets someone who he will later have a brief romance with.

EP Matt Olmstead revealed that Brett and Chili will go through a pretty heavy duty first call in the first episode. He added that Brett, in particular, will be having a hard time because she has developed a fixation on the well-being of a baby.

It was also reported that the citizens of Chicago will work together to protest the drug den in the area. When the crew of Firehouse 51  was called to battle a raging fire, the protest will hinder their duty call.

It looks like "Chicago Fire" Season 4 will answer all the issues raised in last season's finale. It will kick off on October 13 on NBC.