William Powell and Myrna Loy star, a reminder of the time when classy (if drunken) wit equalled box-office success.
The two stars were cheap and boring, that's why their movie flopped.  
mnli hypothesis: The two stars were cheap and boring, that's why their movie flopped.   premise: William Powell and Myrna Loy star, a reminder of the time when classy (if drunken) wit equalled box-office success.