The conditions leading up to Mormon’s personal story are nearly universal rejection of gospel principles. Even worse, “the robbers of Gadianton did spread over all the face of the land; and there were none that were righteous save it were the disciples of Jesus.”
The record keeper Amos, son of Amos, died in the Nephite year 305. His brother, Ammaron, then took up the record. He kept all of the records until deciding, in the Nephite year 320, that the conditions were too unsafe for preserving the records. To preserve them, he “did hide up the records which were sacred—yea, even all the sacred records.” This ends the record that Ammaron kept in the book named for Nephi, son of Nephi.
Ammaron will then look for someone to take up the records. He will find Mormon.