Barbara was coming back in four days- and her father was missing. Once Dinah had heard about the Commissioner's kidnapping (and rested enough after the Riddler's latest set of shenanigans) she started looking for him. It wasn't like it was hard-- not with the neon sign that had been left in all the papers some time ago.
She wasn't going to let Barbara come home to a Gotham without her father-- whether through kidnapping or worse. The Lances and Gordons bled blue and the partnership between the Black Canary and Oracle/Batgirl went further back than either of the two women who held those mantels. If either of Dinah's parents had been alive, they would have been out looking for Jim Gordon. This wasn't something that Dinah thought was optional. This was something that her father would have died to save Jim from-- he would have laid down his life to protect his partner. And Dinah would do the same for hers.
And, just like her parents, Dinah had access to some pretty serious backup that she was more than willing to take advantage of.
The sound of motorcycles filled the Gotham night and they stopped outside of the warehouse. The Black Canary's companion looked over at her as they climbed off their respective bikes.
"You sure about this, Junior?" He asked, looking at the warehouse.
"No. It might be a trap." She supplied skeptically, though she was already started towards the front door.
"I ever tell you how much you remind me of your momma?" He asked rhetorically, chuckling as he followed behind and cracked his neck in preparation for a fight.
"All the time." She muttered, bracing herself for half a second before planting a solid round house kick into the door-- which swung open with no resistance. It had been left unlocked. That was the sign of a trap if she ever saw one, but it was too late now.
Black Canary and Wildcat rushed inside and the hesitation between the two of them at the sight was minimal-- though their reactions were different.
"What in the hell..." Wildcat snarled, scrambling to put chairs beneath the officer's feet-- they were more in danger of dying from suffocation than anything else. Once they were able to hold themselves up, he could get to the dirty business of getting them down from the beams.
While Wildcat was tending to the other officers, Dinah ran up to the glass box that held her father's partner and her partner's father. She didn't know what the green gas was, but it couldn't be anything good. She pounded on the glass twice to let Gordon know that she was there and that everything was going to be alright, then took five wide paces back.
Dinah drew in a deep breath and opened her mouth, letting out an ear-piercing scream that reverberated through the hall, shattering the glass box and several windows. With all of the windows now open and the box shattered, they had plenty of fresh air circulating-- and as long as no one breathed the green gas in directly, they shouldn't have to worry about the effects.
Once the glass was shattered, Canary rushed forward and hauled the Commissioner's arm over her shoulders to help him stand. "It's alright Commissioner. We've got you."