Children of the Underground. The Children of Paranoia Series

Even if you have choices, sometimes you only have one worth making. The war had been raging for as long as anyone could remember. The secret, endless war between two opposing sides-one good, one evil. Neither side knows which is which; it is kill or be killed in an invisible conflict where assassination is the weapon of choice. When she was just seventeen, Maria was pulled into this secret war and they killed her lover and stole her child.
Now they are telling her to go home. To ignore what she knows is going on in the shadows all around her. They told Maria to forget all she'd lost. The trouble is, some things simply can't be forgotten. Now, with a loose-cannon killer at her side, Maria is going to do whatever it takes to get back what belongs to her. And that means starting a war of her own.