Today's readings are from Notebook 5, numbers 1158-1559.
Sister Faustina is experiencing the Darkness of the Soul. We've seen her here before and she always finds her way out of it. However, this reminded me of a letter from the "Screwtape Letters" by C.S. Lewis. Screwtape, a devil, talks about the Law of Undulation, meaning how a soul moves through peaks and troughs. It's during the troughs that a devil can really tempt a soul away from God.