Customs and Border Protection officers found 4 kilos of cocaine in the suitcase of a passenger arriving from Guyana. Homeland Security investigators are interrogating him and trying to find out who he brought the drugs for. Later, a young man from the Dominican Republic is stopped and questioned for his nervous behavior, while a man from Bangladesh comes forward with a confusing story. Meanwhile, investigative units scan luggage on overnight flights with X-ray machines and dogs in search of illegal substances, while postal packages are screened for contraband.