Tension will rise in the next episode of "Chicago Fire" season 4, "I Held Her Hand," when a tragedy pits Casey (Jesse Spencer) and Severide (Taylor Kinney) against each other.

The episode will see the Chicago Fire Department respond to a fire incident a little too late as the woman inside the burning house perished in the fire.

Casey will be devastated about failing to save the victim, but someone will approach him in "Chicago Fire" season 5 episode 5, telling him that he could not have done anything anyway because this woman was deliberately killed.

This leads Casey to think that the fire is no mere accident but actually arson committed by the husband of the victim. He discovers evidence backing up his theory.

However, Severide does not share his opinion and does not believe for a second that the husband, who he said even went back for his wife, could do such heinous act.

With Severide's insistence that the husband is innocent, Casey challenges to prove his claim. From the looks of it, the upcoming episode will not see the end of this feud.

The synopsis for episode 6, "That Day," teases that the two will continue to oppose each other as they investigate on the possible involvement of the husband in the death of her wife.

Casey is in a good position here as he has evidence to prove his claim, while Severide's unacceptable behavior in the recent episodes potentially discredits what he says about the matter as something stemming from the poor judgment from a man in bad shape.

Casey is actually gunning for a promotion and solving the mystery that will ensue in "Chicago Fire" season 5 episode 5 could help him secure that next step to the ladder.

"Chicago Fire" season 5 episode 5, "I Held Her Hand," is scheduled to air on Tuesday, Nov. 15, at 10 p.m. ET on NBC.