During the period of silence, there were many writing about the Jews. But these writings were not necessarily scripture as such. Some are historical - some are fiction - and some are morality tales.
The story of Susanna is both a morality tale - and perhaps a historical tidbit because the older versions of the Bible (before the canon was settled) placed this at the beginning of the Book of Daniel. It was commonly assumed that the Daniel here is also the Daniel of the book.
The moral of this story is that witnesses can be in collusion. Careful examination is required before exacting a death penalty. The woman is vindicated despite the testimony of two elders. Further examination of their testimony - delving into the details - reveals the nature of their lies.
Upon her conviction, Susanna appeals to God for vindication. She knows He is the source of all truth. And it is the Spirit of God that stirs Daniel to intervene.
Whether this story is divinely inspired or not, it testifies to the truth of God and the ultimate triumph of righteousness.
Help us to discern Your words from those of well-meaning but uninspired writers. Quicken the Holy Spirit dwelling within Your children to show us truth from error.
In Jesus' most precious name.