Grettir Ásmundarson is the strongest man in Iceland, unlucky from birth, outlawed at twenty and hunted for nineteen years — he cannot be beaten by any man, and he cannot sleep alone in the dark, because of what he saw in the barrow. Nobody knows who wrote it. The wrestling with Glam is where the whole Northern literature of the undead begins, and Grettir's outlawry is the loneliest thing in the sagas.