Continued Summery

The plane crashed, Lexie died, Arizona lost her leg, Derek's hand was injured, Cristina lost her shoe, and Mark went into heart failure. We know all of this and we know that Mark went on to die once they returned to Seattle. What we don't know is that he had a visitor. Just days after everyone is moved back to Seattle Grace Mercy West a young woman appears out of nowhere. No one knows who she is, all they know is that she's there at the hospital everyday visiting Mark in the ICU. She just sits there and spends hours watching him and talking to him. As time goes on people start to wonder who she is but what will they say when they confront her?