Jailbait: Hero For Hire (2013)

From publisher blurb:

It's tough surviving in the big city when you've run out of money and can't find a job you really want to do (it's not much fun cleaning out stables) so when an admittedly strange person comes up to you offering the chance to earn serious coin who would turn it down? Especially when the job calls for a hero and you're sure you fit the bill.

Breaking into the Khaboom City Dungeons might be possible, especially with the funky key you've been provided with, even if it does mean a trip through the sewer system, but can you be sure that if you do go in you'll ever get out?

And what about the prisoner you're supposed to release? Just who or what do they keep on the maximum security level? Good luck - you'll probably need it!

Hope that's enough to set the scene (or bait the trap!).