I knew that Mormon accounts of the plates used to translate the Book of Mormon say that the angel Moroni took the plates back at some point, but I had a hard time finding the source texts for how or when this might have happened. So far, I have three sources:
 Biographical Sketches of Joseph Smith the Prophet and His Progenitors for Many Generations by Lucy Smith, Lamoni, Iowa, Reorganized Church of Jesus Christ of Latter Day Saints, p. 167-168. Lucy Smith writes:
In a few days we were followed by Joseph, Oliver and the Whitmers, who came to make us a visit, and make some arrangements about getting the book printed. Soon after they came, all the male part of the company, with my husband, Samuel, and Hyrum, retired to a place where the family were in the habit of offering up their secret devotions to God. They went to this place, because it had been revealed to Joseph that the plates would be carried thither by one of the ancient Nephites….(here follows the testimony of the eight witnesses)
After these witnesses returned to the house, the angel again made his appearance to Joseph, at which time Joseph delivered up the plates into the angel’s hands.
I find it strange that the Nephite carried the plates. Did Smith not have them and was he not able to carry them?
 Joseph Smith, History of the Church, 1.60 – Smith writes:
But by the wisdom of God, they remained safe in my hands, until I had accomplished by them what was required at my hand. When, according to arrangements, the messenger called for them, I delivered them up to him; and he has them in his charge until this day, being the second day of May, one thousand eight hundred and thirty-eight.
 Journal of Discourses, Vol.19, p.40, Brigham Young, June 17, 1877. Young’s relates an account from Oliver Cowdery that seems incredibly fantastic and unbelievable.
I lived right in the country where the plates were found from which the Book of Mormon was translated, and I know a great many things pertaining to that country. I believe I will take the liberty to tell you of another circumstance that will be as marvelous as anything can be. This is an incident in the life of Oliver Cowdery, but he did not take the liberty of telling such things in meeting as I take. I tell these things to you, and I have a motive for doing so. I want to carry them to the ears of my brethren and sisters, and to the children also, that they may grow to an understanding of some things that seem to be entirely hidden from the human family. Oliver Cowdery went with the Prophet Joseph when he deposited these plates. Joseph did not translate all of the plates; there was a portion of them sealed, which you can learn from the Book of Doctrine and Covenants. When Joseph got the plates, the angel instructed him to carry them back to the hill Cumorah, which he did. Oliver says that when Joseph and Oliver went there, the hill opened, and they walked into a cave, in which there was a large and spacious room. He says he did not think, at the time, whether they had the light of the sun or artificial light; but that it was just as light as day. They laid the plates on a table; it was a large table that stood in the room. Under this table there was a pile of plates as much as two feet high, and there were altogether in this room more plates than probably many wagon loads; they were piled up in the corners and along the walls. The first time they went there the sword of Laban hung upon the wall; but when they went again it had been taken down and laid upon the table across the gold plates; it was unsheathed, and on it was written these words: “This sword will never be sheathed again until the kingdoms of this world become the kingdom of our God and his Christ.”
If you are aware of other accounts of this event, please let me know.