As a delivery man walked up to the front porch of the Wilson house to drop off a package, he stopped. He caught a glimpse of the backyard, where two girls were dancing together. The soft instrumental piece reached his ears as the girls performed some kind of ballet routine together.
Of course, he recognized Carrie, the daughter of the famous Trevor Wilson, but he hadn't recalled ever seeing the blonde girl over the several years he had been delivering packages to the Wilson's. He noted that while Carrie was a good dancer, the blonde girl was much better — though he didn't actually know enough about ballet to accurately critique it.
He stayed and watched the rest of their performance, feeling like he needed to stay, despite how creepy it may have seemed. Something held him there. As the song came to an end, both girls twirled before ending in a bow.
And then the blonde girl disappeared.
The delivery man leaned back, surprised. It looked as if the blonde girl had just poofed out of existence the minute the song stopped. But he quickly reminded himself that that was impossible. He rubbed his eyes, thinking that he must have just been tired.
He didn't give the blonde dancer another thought as he left the package on the front porch. Besides, she had probably just ran out of his line of sight.
People don't just vanish out of thin air.