Somnambulatory Brew

This concoction looks, smells, and tastes like water. An _identify_ spell reveals that it is imbued with enchantment magic but nothing else. If you drink it, 1 minute later you must succeed on a DC 16 Constitution _saving throw_ or fall _unconscious_ for 1d4 hours. You remain unconscious until you take damage, or until a creature uses an action to shake or slap you awake.