In last week's episode of 'Chicago Fire', the car crash emergency that the members of Firehouse 51 attended to also saw the involvement of Firehouse 20. It was clear in that episode itself that there would be a major clash between the two houses.

While a miraculous rescue was performed by Captain Matthew Casey and Candidate Blake Gallo, the credit for the same in the press was taken by the firefighters of Firehouse 20, much to the displeasure of Hermann and the others at 51.

Of course, the rivalry was only bubbling up in that episode and it looks to be culminating to a dangerous situation in this week's episode.

When a pest control problem means that those of Firehouse 51 have to temporarily bunk with Firehouse 20, members of the two firehouses clash on multiple issues. Under the same roof, tension rises as Casey clashes with Captain Delaney of Firehouse 20, while paramedics Emily Foster and Sylvie Brett, as well as firefighter Stella Kidd fear that Captain Leone has it out for them.

A major fire at a drive-through cleaner proves to be the breaking point as the two captains clash on control and decision-making. The tense situation causes Chief Boden of 51 to think over a procedural overhaul.

One thing fans can be excited about, however, is that Lieutenant Kelly Severide is back at Firehouse 51 after he was let off from the Office of Fire Investigations (OFI) after the events of last week's episode when his rescue of a suspect convinced his chief at the OFI that Severide is best suited to be a firefighter.

Unfortunately for Severide, his return to his family would not be as cheerful as he -- and fans -- would have expected. However, he can provide the backup that Casey needs in order to stand against the captain of Firehouse 20.

'Chicago Fire' airs on NBC on Wednesday nights.