go south (v.)youdaoicibaDictYouDict[go south 词源字典]
"vanish, abscond," 1920s, American English, probably from mid-19c. notion of disappearing south to Mexico or Texas to escape pursuit or responsibility, reinforced by Native American belief (attested in colonial writing mid-18c.) that the soul journeys south after death.[go south etymology, go south origin, 英语词源]