A mysterious young girl named Lela is found electrocuted in the abandoned Morgan mansion. At the request of Police Captain Ryan, private investigator (and suave playboy) Phil Winston takes time out from his carefree social life to help ferret out the murderer.<P>Winston discovers that Lela had facial reconstruction so she would look identical to heiress Marie Morgan. Deducing that Marie was the intended victim, Winston gathers the Morgan family to the decrepit mansion in an attempt to trap the killer. The murders continue. Greed for the family's vast fortune makes everyone a suspect.<P>In one of her first films, Ginger Rogers radiates star quality in the dual roles of Lela and Marie. With sleek direction by Albert Ray, <i>The Thirteenth Guest</i> (aka, <i>Lady Beware</i>) is a riveting murder mystery that is based on a novel by Armitage Trail, best known for writing the novel that became the source material for <i>Scarface</i> (1932).