Severus, Lupin, Sirius.

You were a student at Hogwarts. You were in your third year. It was winter. It was a cool Saturday evening. You went outside with your bag. You came to the frozen lake, quickly put on your skates and started skating. Your movements were smooth and fast at the same time. And then they (Severus, Lupin and Sirius) approached the lake and noticed you. They watched you skate. You didn't notice them and continued skating.