Voldemort was trying to kill Harry when it happened. Suddenly he reflected on his life. He was disgusted that he had killed so many people. The least he could do was spare this one, even though he always thwarted his plans. "Harry," he said, lowering his wand, "I'm sorry for all I've put you through. I don't want to kill you, frankly, you are the only real challenge to my rule over wizarding Britain. Do you want to put the past behind us and become friends?' Harry contemplated the situation. It wouldn't hurt to have a powerful wizard as his ally. He nodded. "Sure," he said, "and if we're friends, then you're invited to my end-of-war party." He Apparated away with a crack.