Batman Begins shortfic
A random possibility based on Batman Begins.
Joe Chill had ratted him out, and that couldn't be allowed. It didn't take much searching to find someone who'd take care of the situation for him; the the Gotham that Falcone had created now provided a constant source of desperate individuals willing to do anything for the chance to escape their lot.
A considerable sum of money--Falcone prided himself on paying a fair wage for good work--awaited his chosen assassin once she'd completed her task. The young blonde woman would never face a day of jail time, either. He'd simply have his pet psycho psychatrist Crane declare her insane and she'd be moved to Arkham, no fuss no muss and safe from prosecution. After a suitable interval Crane would pronounce her "cured" and she'd be free to go with her money and the chance to make a real life for herself. Somewhere *outside* of Gotham, Falcone strongly suggested, and she'd agreed.
The plan, like nearly all of his plans until that Bat-freak showed up, went off without a hitch. Disguised as a reporter, the blonde got close enough to do Chill in one neat shot. She went down without a fight under the pile of cops and bystanders who'd moved too late to stop her. She kept her mouth shut and stuck to the plan, and Crane did his part as well--with a little more glee than Falcone really approved of, but at the time he supposed he couldn't fault the man for taking pride in his work.
Later Falcone would feel sorry for her, if he felt remorse for anyone outside his own cell. She'd been well paid for the murder, but neither of them had counted on Crane's other hobby or the hallucinogenic fear gas the mad doctor had released into Arkham and the Narrows. She'd been caught in the mists like all the rest, and as far as he'd been able to learn from those sources he still had access to, vanished into the warrens of the Narrows without a trace. And without ever collecting the money he'd set aside for her.
Her name--Falcone remembered it only because it'd been so unusual--was Harleen Quinzel.