Harry, as Head Auror needs to do a talk with the fifth years ever year as part of his job. One year he arrived early so to pass the time he looked around the castle. While doing so he finds an object he hasn't seen in 20 years.

What if Harry had a Guardian Angel that, once a year visited him told him one cryptic message and left. Every year before Hogwarts all she did was give him vital stuff for his growth but at Hogwarts he really meets her.