let the genie out of (or put the genie back in) the bottle let loose (or bring back under control) an unpredictable force, course of events, etc.

☞ A genie or jinnee in Arabian stories is a spirit that can adopt various forms and take a mischievous or benign hand in human affairs. The genie generally inhabits a lamp (compare with Aladdin's lamp ataladdin) or bottle from which someone can release it by the appropriate words or actions. The Arabic word appears in English in various transliterations; genie derives from French génie (from Latin genius meaning 'a tutelary spirit'), used by the French translators of The Arabian Nights because it was similar in form and sense to the Arabic word.

2005Time Nobody thinks the gambling genie can be put back in the bottle.