Drowsy Drop is an item in Tyranny.
Mercenaries within the Tiers use Drowsy Drop to inflict sleep upon their foes. Any alchemist will claim that it's easier to brew a poison than a soporific, which is why only masters of the art are granted dominion over their making. The delicacy and specialized skill it takes to balance ingredients increase the value of the final product, but also guarantee quality results. Sleeping draughts are also used to immobilize captives for future interrogation.