I'll be honest- I didn't warm up to Burgess from the start of the series. When she was in patrol, I found her to be a naive, idealistic Pollyanna. I'm getting that was starting point of the character's arc as intended by the writers. You start to see her resourcefulness and independence take form in Season 2's 'What Do You Do', when she has to defend an incapacitated Roman and herself against gang members in an abandoned building. In Season 4's 'Last Minute Resistance' Burgess, partnered with Lindsay, in the process of carrying out a sting on two would-be rapists following the instruction of a purported pick-up artist guru, deliberately downs a cocktail she knows is roofied to ensure the suspects follow through with an overt act that is sufficient for conviction. Afterward, Sgt. Voight calls Burgess out for ingesting the spiked drink, but is ultimately convinced that she is a good fit for Intelligence. In Season 7's 'I Was Here', while on light duty taking calls at a 911 call center, she takes a call which concerns her enough that she does a follow-up with Platt on scene, even after two uniforms respond to the scene earlier, which results in her uncovering a sex-trafficking ring. While only a fraction of the Burgess-centric episodes in the whole of the series, these form a through-line to where the character goes in tonight's 'Rage'. As evidenced by the conclusion of this ep, Burgess is at her apex on the job when she walks the razor's edge between initiative and recklessness.