When No.2 is on the telephone speaking, presumably to No.1, it is not difficult to assume that No.1 has expressed the wish that he could be there at the Ball in the evening judging by No.2's response "Yes, I wish you could come too."
If No.1 had turned up at the Ball in the evening, that would have livened things up a bit. But then how would we know? How would No.6 know that the man behind the big door is there? Everyone will be in fancy dress and some wearing masks!
Be seeing you