My Sister Rosa by Justine Larbalestier

Have you ever seen "The Bad Seed"? If you haven't go watch it now! If you have you will understand when I say Rosa is Rhoda reincarnated.

Che knows something is wrong with this sister Rosa, yet he has a need to protect her. Rosa is wise and clever beyond her years - in fact she is brilliant. Rosa has a menacing way about her and no one believes Che when he warns them. Her cherub looks and manipulative ways makes it easy for others to look the other way and see her as anything but a sweet, intelligent child.

Che constantly has to make Rosa "promise not to do bad things" but she finds a way around her promises. She is a ticking bomb ready to go off and people's lives are a stake.

This is a creepy tale that moves along quite nicely. I was expecting more based on the write up but overall was left satisfied.