The Failure Chair

Zariah is a bounty-hunter. If you need someone or something found that has slipped your grasp, Zariah can track it down and bring it back to you. Mostly in one piece.
She doesn't come cheap though, so anyone hiring her will need a lot of souls to pay her fee, and she always collects, one way or another.
Her last job was a big one. Shegorah - The Baroness herself - hired Zariah to bring back an escaped underling name Zukka. Should have been a piece of cake; Zukka was only a lowly Succubus, a bottom feeder. The job would have set her up for decades, if her mark didn't escape.

When your boss is a Baroness of Hell, you really don't want to screw up.