Sigyn (also spelled Siguna), in Norse mythology, one of the Asynjur goddesses, and the wife of Balder, was finally captured by the Aesir gods. He was taken to a cave and bound to three stone slabs. The goddess Skadi then set a poisonous serpent above Loki's head so that the burning venom would drip onto his face. There he was doomed to remain in his bonds until Ragnarok, the final battle between the forces of good and evil, when he would break free and lead the denizens of the underworld in battle against the gods. Until that time, Sigyn, his faithful wife, crouched between him and the huge serpent above his head. She patiently caught each of the drops of poison in a basin. Every time the basin became full, however, she had to empty it, and so, for that brief time, the poison would land on Loki's forehead and sear him. Then he would writhe in agony and pull at his bonds, and the Earth rumbled and shook from the force. This was the Norse explanation for earthquakes.