Rev-up Vitamin Shots

Despite the name, a drunk rather than injected dose: a powerful, race-specific sedative handed out one at a time to the Iron Tangle's migrating mobs by a Pooka boss at each five-stop tunnel, meant to keep them compliant and looping the train lines on schedule. Doesn't take effect until swallowed on the far side of a one-way portal back to the mob's own station; missing a dose in time is reported to cause a physical change in the user.