[s1e6] Rear View Mirror -

: It finally brings the intense conflict between Matthew Casey and the corrupt Detective Hank Voight to a head, resolving a storyline that had been building since the pilot.

: Casey puts his life on the line during a massive apartment building fire, leading to a high-stakes rescue that ultimately provides the break he needs to take down Voight. [S1E6] Rear View Mirror

: While Casey deals with external threats, Gabriela Dawson faces a disciplinary hearing for her own past actions, where she receives unexpected help from a girl she previously saved. "Chicago Fire" Rear View Mirror (TV Episode 2012) - IMDb : It finally brings the intense conflict between

It sounds like you're referring to which is the sixth episode of the first season of the NBC drama Chicago Fire . [S1E6] Rear View Mirror