This one is tagged as adult but I think a lot of YA readers might like it too.
Faina, ward - or hostage - to a noble house - dances dreamily through the days, and fails to fit into her current life.
Sorrow, the almost invisible assassin, kills but then weeps black tears over the corpses.
Lord Ash, right hand of the king, adviser, investigator and if need be also assassin, comes to solve a spate of recent noble killings, a breath of very cold air among the wealthy and well born.
This is a story that's going to stick in my mind, so I'm passing it along to yours. The plot is suitably twisted, the ending not perhaps what you will expect, and the characters strong and fairly unique. And the writing, or the overall impression, was... haunting.
Try it and see if you agree?
Sorrow, from Dragonwell Publishing, came out in September.