Bonnie Sheila Bennett (based on Bonnie McCullough from the novels) is Elena Gilbert's best friend. She is also good friends with Caroline Forbes. In the beginning of the series, Bonnie discovers that she is born from a line of witches and that she is also a witch. Her grandmother, a witch too, helps her learn to use her powers, which causes them to create a strong bond. When her grandmother dies, Bonnie is devastated, but she keeps training and as the series develops she becomes more and more powerful. In the midst of season two, she starts a relationship with Jeremy Gilbert, Elena's younger brother. She later discovers from warlock Luca Martin that the only way to kill Klaus, the original vampire who wants to kill Elena, is for her to get the power of one-hundred dead witches, which she later gets. She then pretends to be dead, a scheme of Damon's, in order to trick Klaus. But when she brings Klaus to the brink of death, Elijah does not kill him, as planned, and carries him away before she could react.