The caster recites a verse that enables this spell just before he goes to sleep and, as he enters the dreamworld, his body becomes ethereal. He is now located somewhere between the two worlds and cannot be harmed by normal weapons, as he is now both invisible and incorporeal for as long as he sleeps. This spell is useful against assassins, though it does not make the caster invincible but merely incorporeal. Many adventurers find a good use for this spell when they are travelling, as it guards them when they sleep in the wild lands.