Alicia and AJ (and intervening judges, bystanders, etc...)
AJ and Alicia happened to time their arrival right before the 5-minute pause at 9, which was perfect for their attempt to slip onto the dance floor undetected when the dancing kicked off again. There were enough couples still in play that they could try to blend in, but they were fresh and full of energy as some of the others around them were starting to fade.
"I'm feeling very good about our chances!" AJ shouted into Alicia's ear, over the music, then attempted to twirl her, somewhat clumsily. He could keep the beat well but he didn't exactly have any "moves."