The sword and the stitcher

An impoverished young sewer, Evelynn has never known adventure. Her brother, Griff, always has, passing daringly through the city and securing her food through unsavoury connections. Until now, she has never known his methods. Now that she does, Evelynn is ready to join the underworld just like her brother.

But what can a young girl offer the underground, that it can't just take?