"Just give me a motive: name somebody who might conceivably eat, drink, or otherwise ingest something you´ve touched. If it´s an NPC, roll+hard; a PC, roll+Hx. On a 10+, they do, and suffer 4-harm (ap) sometime during the next 24 hours. On a 7-9, it´s 2-harm (ap). On a miss, some several people of the MC´s choice, maybe including your guy maybe not, get it, and all suffer 3-harm (ap)."
Ok, I just don´t get the move, I mean, I understand how it works, but I can´t just explain that in the fiction... Why something you´ve touched? Why do and suffer harm? Does it represent the Maestro D´ inciting a traditional bar fight? Is it something more esoteric or weird?