Divine Mercy in My SoulDiary, Sister M. Faustina Kowalska
[…]It was at that time that I asked the Lord who else I should pray for. Jesus said that on the following night He would let me know for whom I should pray.
[The next night] I saw my Guardian Angel, who ordered me to follow him. In a moment I was in a misty place full of fire in which there was a great crowd of suffering souls. They were praying fervently, but to no avail, for themselves; only we can come to their aid. The flames which were burning them did not touch me at all. My Guardian Angel did not leave me for an instant. I asked these souls what their greatest suffering was. They answered me in one voice that their greatest torment was longing for God. I saw Our Lady visiting the souls in Purgatory. The souls call her “The Star of the Sea.” She brings them refreshment. I wanted to talk with them some more, but my Guardian Angel beconed me to leave. We went out of that prison of suffering. [I heard an interior voice] which said, My mercy does not want this, but justice demands it. Since that time, I am in closer communion with the suffering souls.