Robert Jordan had repeatedly said that the main sequence would conclude with the twelfth book, with a working title of A Memory of Light. Numerous times, including most recently on ComicCon 2006, he said he would hold to this statement even if it has to be 1500 pages long. Before his death Jordan had planned to write two more short prequel novels, an encyclopedia, and possibly two or three other side-plot novels.
With RJ's death on September 16, 2007, the conclusion of the series was in question. On December 7 the publisher, Tor Books, announced that fantasy author Brandon Sanderson would finish A Memory of Light.