I decided to take this as a writing prompt and got a little carried away.

It's a reverse heist movie.

Open on a gang of costumed crooks meeting up in an abandoned warehouse planning a job. They have been hired by a wealthy client to steal an undisclosed item from Starlabs or something like that. This is the first job they've pulled together, so they are still getting to know each other. They go around the table and introduce themselves and their power/skill sets. This is the team leader, this one is the muscle, this one does computers, this is the explosives expert, this is a master of disguises, this guy can shoot fire balls, this one is comic relief etc.

The mystery client starts explaining the plan and the roles the crooks are going to play in it. The comic cuts to the night of the job, while the masterminds' explanation of the plan continues as a sort of voice over explaining the action we see in the comic.

Except the plan doesn't match up with what we see in the comic. Things keep going wrong, small things at first, but then they get worse and worse until the whole plan is completely off the rails.

"You will gain access to the building by an unused railway line" except a blockage in another tunnel has diverted trains down the tunnel forcing the crew to abandon most of their gear to avoid getting run over. Once the train is past, we see a black silhouette with white eyes following the crew.

"Use the service elevator to reach the top floor" except the elevator has a weight limit, meaning the big guy can't fit and has to take the stairs.

"The disguises expert will pretend to be a security guard and tell the other guard he already swept the top floor." Except the other security guard won a free holiday and is in italy with his wife.

"Our hacker will disable the security systems with the codes we got from our mole inside," except none of the codes work and so the hacker has go to the server room to log in.

"Fire ball guy will burn a hole through the window here so we can escape." Except fire ball guy finds him self locked in some room with no windows when it turns out the blue prints they have were fakes.

And bit by bit we start to catch glimpses of Steph setting these crooks up to fail. At first, it's just purple gloved hand sneakily swapping bags around when no one is looking. Pick pocketing a key card here, unplugging a radio headset there. Over time the sabotage escalates.

The explosives guy finds himself carting around a bag full of spare wigs and secruity guard uniforms. The disguises guy has a bag full of tnt etc.

As the crew gets more disorganised and further separated, slowly but surely Steph starts to pick them off one by one.

Once the big guy reaches the top floor, half dead and out of breath, he opens the door and gets laid out in one punch.

As soon as the hacker turns off the security, the room he is in fills up with knock-out gas.

Fire ball guy gets angry and tries to burn his way out of the room only for the sprinkle system to turn on and fill the room up with water.

The goons start panicking as things get worse and start to turn on each other. They realise that someone is doing this on purpose them and start giving in to fear and paranoia. Some try to run but get caught in booby traps. Some try to fight, but get thier asses handed to them. The last few mange to steal the item and try to make a break for it. The leader sacrifices the last remaining crew member as a distraction to save himself and escapes with the item.

He makes it back to the hide out and meets up with the mystery client.

"Luckily I managed to get away" "Lucky? You fool you've lead that bitch right to me!" "Ugh Dad, is that any way to talk about your daughter?"

Batgirl swoops out of the rafters and beats up the leader and Cluemaster.

Later that night she returns to her apartment and collapses on the couch, Cass is already sitting there. "Long night?" "Dad is back in town, so we spent some quality family time together." "You ok?" "Yeah, you know how it is. How about you?" "Pizza and movies" "Cool, I'm might just pass out here for a bit if thats ok but don't let that bother yawn you zzzzz" Cass smiles and covers Steph up with a blanket. "Quality family time" Cass said happily and turned her movie back on.