Back at the Blue Moon's Pack, the same time:

Shane, Curtis and Clem are with Anthony in his room, lounging on his bed, since Derek had refused to see any of them after Emma had left.

Rewind to last night at the hall, when Emma had left the hall:

When Emma had left the party with the vampires right behind her, Derek had turned around immediately, and had left the party hall, amidst the murmurings that had arisen from the event that had just occurred, and for once, even if it was for one tiny witty second, he didn't look at Claire who had still been sprawled on the ground,...