A routine inspection of a cargo ship uncovers a well-hidden, illicit load; weapons smugglers attempt to evade authorities; a luxury boat comes on the radar; agents locate a ship filled with people smugglers trying to make landfall.

HSI agents coordinate a massive raid to take down a transnational drug trafficking gang; agents interdict an erratically moving vessel, often a sign of evasive smugglers, but it turns out that its passengers have less sinister motives.

Officers race to Port Newark, where a West African car gang is getting ready to ship a stolen luxury vehicle out of the country; using the owner's GPS tracker on the car, they attempt to identify the container it's in before the ship leaves port.

Agents investigate a small boat crewed by three men on a well-known smuggling route, only to confirm the men have a shady past; an agent finds life jackets and clothing abandoned on the beach, evidence of a recent illegal migrant landing.

Agents must abort a mission when an incoming tropical storm rolls in; a cruise ship passenger balks at paying U.S. duty on cigarettes; Illicit packages dumped at sea begin washing up on Florida's beaches; a Brazilian vessel intrigues agents.