Flicker .

Marissa Haro is a geometry whiz. She can calculate angles and force so accurately that often she can correct the books mistakes. But all of this isn't just a coincidence. Marissa can see the angels, she can understand how much force should be applied to an object to make it do certain things. She's never taken a swing at someone and not knocked them out.

But Marissa has always thought that she was just gifted. She never knew that there were others like her out there. She also never knew that some people would kill for their gifts, kill to make them disappear.

And this is only just the beginning.