Dossey traces the fear of the number 13 ~ aka, triskaidekaphobia ~ to a Norse myth about 12 gods having a dinner party at Valhalla, Norse mythology's heaven. In walked the uninvited 13th guest, the mischievous god Loki. Once there, Loki arranged for Hoder, the blind god of darkness, to shoot Balder the Beautiful, the god of joy and gladness, with a mistletoe-tipped arrow. "Balder died, and the whole Earth got dark. The whole Earth mourned. It was a bad, unlucky day," Dossey said.
Quantum Spirit: Triskaidekaphobia Has Several Ancient Sources