The Hebrew book of Esther does not mention God. No divine name appears in it, nobody prays in it, no miracle occurs, and no prophet speaks. This is unique in the Hebrew Bible and it was noticed early: Esther is the only book of the Tanakh of which no copy has been identified among the Dead Sea Scrolls, and rabbinic sources record debate about whether it belonged in the canon at all.
The book's answer to the problem it creates is oblique and deliberate. When Esther hesitates to approach the king, Mordecai tells her that if she keeps silent, relief and deliverance will arise for the Jews from another place, but she and her father's house will perish, and asks who knows whether she has come to the kingdom for such a time as this. Relief from another place is as close as the Hebrew text comes to naming providence. The plot then turns entirely on coincidences that the reader is left to interpret: the king cannot sleep on exactly the right night, and has the chronicles read to him, and the passage read is the one recording Mordecai's unrewarded loyalty.
The Greek version of the book solves the difficulty by removing it. The Septuagint carries six substantial passages absent from the Hebrew, including prayers by Mordecai and Esther, an explicit account of divine intervention, and a scene in which Esther faints before the king and God turns his anger to gentleness. These Additions to Esther are canonical for Catholic and Orthodox Christians and placed among the apocrypha in most Protestant Bibles, so the same figure exists in two versions, one in which God is never mentioned and one in which she prays at length.