Wonderfully weird kitsch is what every droopy soul needs during the post-holiday doldrums. And there’s no better place for good old American middle-class strangeness than the Marriott West Loop Hotel, where the Mystery Cafรฉ serves up London broil, penne pasta and a show every Friday and Saturday night. The newest production, Come Up and Slay Me Sometime!, features gangsters, girls and giggle water, and promises to sweep the audience back to the prohibition era. Mae West, Charles Lindbergh and Freddie “The Noodle” have all gathered at the “largest floating speakeasy in history,” but a dead body is found just as the party is about to go live on the radio.