Sam and Callen have spent time undercover as CHP officers looking into a gang of corrupt officers known as the Golden State Taxi Service.
Those people who give safe passage to smugglers and criminals across a major U.S highway with suspected ties to Marines at Camp Pendleton.
They are getting closer to the truth when they find the gang leader shot and barely alive but soon dies. Eric helps them track their #2.
She tells them Pat was approached about a job with a big pay-off but when he said no they killed him.
Callen has a plan and tells Jennifer to put the word out that the gang is back in on the plan and she is putting her two best guys - Sam and Callen.
They meet a businessman that says all he needs them to do is stop the SUV of a business rival and arrest him and a big pay-off with come to them.
The team doesn't see what this has to do with Marines but follows the plan and find themselves in an ambush.
The SUV was filled with the businessman's crew and the real plan was to steal a nuclear warhead that was making its way to be refurbished.
The team races against the clock to find the warhead when they discover a young physicist to is kidnapped by the group to activate it.
NCIS overcomes them and their plot - create mass hysteria to capitalize on a Wall Street sell-off - in the end.