Slave milk is the common name for an alchemically-enhanced drug created from an opiate base. It acts on a human body in various ways to enhance sexual arousal, suppressing inhibitions and sensitizing the skin to enslave the mind to the body and senses. It is highly addictive, and as of CE 580, there is no known cure. Addicts typically die within months, burned out from the inside by sexual hunger they can no longer control.
Slave milk is illegal in all of the nations that made up the Alliance in the Great War. Getting caught in the manufacture, distribution of slave milk, or causing a sentient being to be addicted to it is, in Fernwall, grounds for an immediate life sentence in a collar of indenture.