In these dire circumstances, where does Belshazzar seek help? Not from the Lord! He does not even think about the Lord, even though he has been drinking from the cups of the Lord. You cannot come up with an excuse for the king here. He knows what the Lord did in the time of Nebuchadnezzar. That becomes very clear in what Daniel says in Daniel 5:22: And you his son, Belshazzar, have not humbled your heart, though you knew all this.
Belshazzar does not want to acknowledge the Lord as the Almighty God. He again seeks his help from the idols and the wise men who are in the service of these idols. He does so, knowing that these people cannot really help. He does so, knowing that the wise men in all their various functions have admitted, in the time of Nebuchadnezzar, that they have no real contact with the gods.
7 The king called loudly to bring in the enchanters, the Chaldeans, and the astrologers. The king declared to the wise men of Babylon, “Whoever reads this writing, and shows me its interpretation, shall be clothed with purple and have a chain of gold around his neck and shall be the third ruler in the kingdom.”