They could be the earliest Christian writing in existence, surviving almost 2,000 years in a Jordanian cave. They could, just possibly, change our understanding of how Jesus was crucified and resurrected, and how Christianity was born.
A flash flood had exposed two niches inside the cave, one of them marked with a menorah or candlestick, the ancient Jewish religious symbol.
A Jordanian Bedouin opened these plugs, and what he found inside might constitute extremely rare relics of early Christianity.
That is certainly the view of the Jordanian government, which claims they were smuggled into Israel by another Bedouin.
The Israeli Bedouin who currently holds the books has denied smuggling them out of Jordan, and claims they have been in his family for 100 years.
Jordan says it will "exert all efforts at every level" to get the relics repatriated.Incredible claims
The director of the Jordan's Department of Antiquities, Ziad al-Saad, says the books might have been made by followers of Jesus in the few decades immediately following his crucifixion.
"They will really match, and perhaps be more significant than, the Dead Sea Scrolls," says Mr Saad.
"Maybe it will lead to further interpretation and authenticity checks of the material, but the initial information is very encouraging, and it seems that we are looking at a very important and significant discovery, maybe the most important discovery in the history of archaeology."
They seem almost incredible claims - so what is the evidence?
The books, or "codices", were apparently cast in lead, before being bound by lead rings.
Their leaves - which are mostly about the size of a credit card - contain text in Ancient Hebrew, most of which is in code.
If the relics are of early Christian origin rather than Jewish, then they are of huge significance.