On their way to Monte Carlo, Monaco, Marilyn and her husband, Neil, meet several other married couples, including Julian and Phoebe, who are traveling with a lost dog they plan to return to its wealthy owner for a large reward. But, when the dog's mistress is murdered, the travelers become the prime suspects, and Inspector Bonnard is determined to track them all down.

The renowned Insurance International Co. has created an enquiry network, headed by detective Jack Clementi, to defend itself against insurance fraud. Jack has saved the company enormous amounts of money throughout his successful investigations and his bosses are more than willing put up with his brusque manners, his disconcerting frankness, and his intolerance for any form of company bureaucracy. Yet he is a big guy with a huge heart.