The series begins with a search for undocumented immigrants along the U.S.-Mexican and for smuggler's in Canada who have been sneaking drugs into the country inside of baby diapers.
CBP officers may have struck paydirt when at the Detroit Metropolitan Airport when they chat with a couple who are headed to Dubai who are carrying piles of undeclared cash and tell conflicting stories. A suitcase emitting a strange sound quickly empties out the terminal of Miami International Airport for an emergency evacuation. An officer at the San Francisco Mail Center makes a grisly discovery when he X-rays a box from China and is shocked by what he finds. At the Ysleta port of entry in El Paso, Texas, where one quarter of all illegal drugs entering the U.S. are seized, officers rip apart a sedan in search of its secrets, while a bag search prompts a deadly avian flu quarantine at the JFK airport in New York.
When the customs officials in Buffalo become suspicious of the story of a Turk emigrating to Canada, the result is being separated from his wife and child. Then, officers in El Paso pay close attention to a canine inspection of an SUV. Also, the security officers in Pittsburgh get into a discussion with a student from MIT over passengers rights, and a mail center in New York inspects a package which arrives from Afghanistan.
The Coast Guard in Florida tickets a man for riding his Jet Ski in protected waters, and a fishing boat full of suspicious cargo and a man fleeing from the scene has the customs officers in Puerto Rico on alert. Also, a man in New York is questioned concerning the Nathalie Holloway disappearance case; and a trained beagle has his senses set on a passenger's lunch.
An airline passenger is detained in Miami when a large sum of cash is found on her; agents at the Texas-Mexico border stop a bus traveler; sixteen women crossing the border from Canada are stopped after claiming to be going to the U.S. for a bachelor party; and in Alaska, husband-and-wife agents carefully mind the Canadian-U.S. border.
A convicted sex offender with an outstanding warrant is arrested at an airport. The U.S. Coast Guard saved many lives in New Orleans when hurricane Katrina wrecked havoc.