Mackenzie is a common girl in an ordinary school.This can be something that can happen to you.One day, Giselle, her best friend disappear. Mack didn't knew why, but everyday a letter come and says: Be careful, I know everything of you but no one knows something about me...you are in danger 😼XaXo. Mackenzie knew that name but from where, she thought that her bff told her something about XaXo that he was...a killer. But why him or her kill Giselle? If he was a killer, why the school didn't notice? Giselle recived this letters before and then disappear? I will disappear? [EDITING]