At the behest of another relative, Jessica dutifully travels to New Orleans to check on a distant cousin who hasn't kept in his usual close contact with the family. Through a series of events she arrives just in time (of course) and at just the right place, for another murder.
Fortunately, although the murder happened at a Mardi Gras party in which nearly everyone was wearing an elaborate mask and costume, Jessica is able to recollect every minute detail from the evening and piece it together with other subtle observations to deduce who the real murderer is, among all the motivated parties who were gathered.
This episode had all the key ingredients of a great whodunnit: mobsters, politicans, police, paired up with lying, illicit gambling, and betrayal. Combine that with Jessica's steel-trap mind and you have another great installment.