Joel and Garda Sloane, a husband and wife sleuthing duo, sell rare books in New York and dream of taking a vacation to escape the sweltering heat of the city. Joel decides to take Garda to Seaside City, where his pal, Mike Stevens, is managing a popular beauty pageant. In addition to his vacation plans, Joel, who has invested $10,000 in the pageant, plans to supervise the financial developments of the event and "keep an eye on" the contestants. Soon after arriving in Seaside City, Joel discovers that Eric Bartell, the unscrupulous promoter of the pageant, is duping Stevens. When Joel is made a beauty judge by Stevens, Garda balks at the appointment, especially when her husband begins to socialize with the contestants in the days prior to the pageant. Joel senses trouble when New York racketeer Ed Connors arrives to monitor Bartell's activities, and when Lily Cole, Bartell's publicity director, lashes out at contestant Jerry Lawrence for vying with her for Bartell's attentions. Joel is convinced that something foul is afoot in Seaside City when a detective tells him that Bartell will be arrested on swindling charges as soon as a warrant is issued. When Bartell is mysteriously murdered, Stevens, who was the last person seen with Bartell, is arrested. Stevens is suspected of the crime because he went to see Bartell to demand that he return all the money he loaned him. Although Joel and Garda are warned by Chief Miller not to get involved in the case, the duo, with the help of newspaper columnist Ted Bentley, begin to investigate the murder. Soon after, an attempt is made on their lives when a falling elevator nearly crushes them. Joel does not believe that Stevens was the murderer, but instead suspects Lily, because she and Bartell were involved in a dispute prior to the murder. Later, when Joel discovers that Jerry smokes the same brand of cigarettes as the one found smoldering at the scene of Bartell's murder, he interrogates her and she names Connors as the murderer. Connors, overhearing her accusation, attacks her and tells Joel that she is merely trying to frame him. When Jerry is found murdered, Joel deduces that the murderer must be Bentley, because he is the only person who knew that he had proof against Jerry. Joel tricks Bentley into confessing his guilt, but Bentley, in an attempt to silence Joel, tries to kill him. However, he is prevented from doing so by the police, who arrest him. Eventually, Joel learns that Bentley killed Bartell because Jerry threw him over for Bartell, and that he killed Jerry because she knew too much.
