Chasing the dragon
"Chasing the dragon" (CTD) (traditional Chinese: 追龍; simplified Chinese: 追龙; pinyin: zhuī lóng; Jyutping: zeoi1 lung4), or "foily" in Australian English, is the act of inhaling the vapor of a powdered psychoactive drug off a heated sheet of aluminium foil. The moving vapor is chased after with a tube (often rolled foil) through which the user inhales.