After taking part in an investigation in Honolulu, Hawaii, G and Sam return aboard a military aircraft to Los Angeles; two detectives, Danny Williams and Chin Ho Kelly, from the task force called Hawaii Five-0, accompany them; they together seek to intercept a rogue epidemiologist, Prodeman, who stole nine vials of smallpox virus; Prodeman's traveling companion dies of hemorrhagic smallpox before landing at the LAX airport aboard a commercial flight; Prodeman eludes capture and leaves the airport. Sam and Chin tackle Prodeman near his motel; he gives the name of Dr. Rachel Holden, whom the team pursue; Kensi and Deeks play nurse and doctor and produce results; G turns over a motor home, but the team does not find any stuff; still, though, they figure out the whole thing, then they find the bad woman, who holds alternative views and acts on them, and they not only interrupt the distribution of free T-shirts but also prevent a disaster of unimaginable proportions.
—DocRushing