The scheme worked through Peter's use of three social engineering tactics. First he got Mary's initial cooperation by generating fear—making her think that her computer might not be usable. Then he took the time to have her open two of her applications so she could be sure they were working okay, strengthening the rapport between the two of them, a sense of being allies. Finally, he got her further cooperation for the essential part of his task by playing on her gratitude for the help he had provided in making sure her computer was okay.