'Chicago Fire' season 5 spoilers: Casey and Dawson continue fight to be Louie's legal parents; Severide risks breaking a promise for bone marrow patient

"Chicago Fire" season 5 will be back with brand-new episodes next year. NBC has released sneak peeks and promotional stills for the second installment of the show airing next year.

After teasing the first episode of the new year, "Some Make It, Some Don't," NBC teases the next one, which will see Casey (Jesse Spencer) and Dawson (Monica Raymund) continue their efforts to be legal guardians of little Louie.

They hit a snag in the "Chicago Fire" season 5 winter finale, in which the kid's biological father showed up and was revealed to have been closely following Casey and Dawson.

In a sneak peek for "Chicago Fire" season 5, episode 10, "The People We Meet," which happens to be a crossover episode with "Chicago P.D.," Casey and Dawson seek the best adoption attorneys in the city to help them win permanent guardianship, despite the greater odds of Louie's real father getting the custody.

However, things are about to get even tougher for the newlyweds. Entertainment Weekly teases a "bumpy" journey for the two in "Chicago Fire" season 5.

More interestingly, the publication also teased "an interesting twist when it comes to his bio-dad" that could leave fans "feeling bad for the guy."

A "Chicago Fire" season 5 sneak peek for episode 10 shows Severide (Taylor Kinney) pledging his commitment to a bone marrow donation.

The doctor emphasizes to him over and over about the importance of his involvement and assurance as once it is started, there is no turning back. Quitting in the midst of the process will lead to the death of the patient.

It is not quitting that it is to worry about though. The synopsis for "Chicago Fire" season 5, episode 10 teases that a work accident will send the bone marrow donation into flux.

Apart from this, Severide will also have to deal with going on a double-date with his ex Lindsay (Sophia Bush) and her boyfriend Halstead (Jesse Lee Soffer) and being framed for a hit-and-run incident.

"Chicago Fire" season 5 will return to the small screen on Tuesday, Jan. 3, at 9 p.m. ET on NBC with "Some Make It, Some Don't."