It would start with a girl waking up bruised and bloody, lying on the ground. Two men are standing over her, talking about her. One says, "She doesn't know anything. Finish her off." And leaves.
She manages to escape before she can be killed. But she doesn't know who she is or what they wanted to know. (And at this point, I have no idea either.) So she has to figure it all out.
I told Teen my idea, and she said, "Too many ideas and not enough writing. Get to work!"
She might have a point.