The Nwyfre Runestone was stolen from a group of angry Druids by the Librarians and brought to The Library.
Powers
The Nwyfre Runestone's magical abilities are as yet unrevealed.
Real Life Counterpart
Runes were a sacred alphabet used by ancient Germanic People. It was used to write all kinds of texts: commemorative, magical, poetical, many of which were written in stones. Today, they are considered dead as a language but are common in popular culture and in certain kinds of religion.