A sci fi romance novella set in a beautiful world that is ruled by close-knit mafia-type families. 
 Meli is an assassin, a hidden resource for her family. Her last assignment is to kill the man who ruined her life years ago by breaking their engagement. Meli had been trained in Celino's likes and dislikes from a very young age in preparation for their eventual marriage. She uses this information to get close to Celino. 
 Celino, a financial genius, is drawn to the mysterious woman who fits so seamlessly into his life. He doesn't know that they've met before, that he has a lot to make up for, and that she could kill him at any minute. 
 In most He Done Them Wrong books, the male lead seems to get off too easy - he drops a smoldering look, maybe some "I'm sorry's", add in some sexual chemistry and all is forgiven. Not here. Meli freaking breaks Celino. Epic groveling (we are not talking days or weeks here - think longer). And still it works as a romance. I was rooting for them. 
 I need to go re-read this one again.