Marking is the first step in changing into a fledgling. Before someone is Marked, they begin to get sick in a way that resembles the common cold or the flu. Then a Tracker tracks them down, raises their finger to their forehead and says the incantation:
The person then feels pain in their forehead. They are then left with a unfilled cresent moon where they felt the pain. It seems that a person can now be Marked with either a sapphire blue or red color moon, as Shaylin Ruede was the first to be marked with red and was the first of Erik Night's.
If the fledgling doesn't get to a House of Night, specifically the adult vampyres, soon after being Marked, their sickness will worsen and they will die.