Every hour, any creature within range of the touched creature must make a Will save or fall asleep. After 3 hours of this effect, it becomes apparent (with a DC 20 Spot check) that the touched creature is immune to this effect. If the touched creature is killed or knocked unconscious, the spell is instantly dispelled and all creatures put to sleep by this effect wake up. Unlike with most spells, the save DC of this spell is equal to 15 + the touched creature's character level.