As they circled each other to size each other up for the duel, it hit me. It wasn't just love that was the power, but the melding of Gryffindor courage and Slytherin conviction. This was the power that he knew nothing of. Elbowing my wife, I accepted the strength and power that came from the Compulsion. The resolve in Narcissa's face told me she knew what I was going to do.