Kara has always had the keenest awareness of the perceptions of others. It started in the combat zone when she and her sibling would have to slip through the violence and lawless madness every day to find food or tech scrap to sell. Those kids who didn't learn, on an instinctual, beneath-thought, kind of level were all dead. But Kara had become the best, she'd slip into the gang hideouts and bases, steal whatever she could get her hands on, and out again before anyone knew the difference.
This evolved once she reached adulthood, and she discovered just how effective a distraction a pretty face and a tight body could be. So, when they hit the roof, she leaned into shadow and raw concrete to shield her from view. There was a heavy steel roof access door, built like a trapdoor in one corner, there primarily for the maintenance grid for the networking and power cabling within. Kara watched the Chameleon approach, a little fascinated by the shifting colors and thinking, I really gotta learn how to do that.
She focuses on the lock, a complex series of failsafes, alarm chips, and self-testing sensors. But she grins, these locks are pointless if you know the trick. She slips a small length of wire, no more than a paperclip really, and casually slips it into one gap before sticking out her tongue and fiddling for a short time. The red padlock symbol flashes green and then fades dark with a click.
Kara can't help but grin at Camilla, then she silently slides the trapdoor open, turn her hair black, and lowers her head into the narrow shaft. She then flickers her eyes up to Mercy, judging that the man will fit... Just. With no more hesitation, she slips into the maintenance duct and starts wriggling in an enticing manner until she disappears, hoping to make it to a storage closet, or some other unmanned spot to slip into the building proper.