Jesse Evans, a Homeland Security agent, gets poisoned at a pool party. The team is assigned to look into Evans' death, as he is the second Homeland Security agent killed in a month.
Nell is again partnered up with Deeks. Evans' friend Carlos tells Deeks and Nell that they got invited to the party by an anonymous beautiful woman. Granger explains to Callen and Sam that that beautiful woman was Ming Wah, a Triad assassin, who was at the pool party.
The squad goes to a warehouse that belongs to Chinese businessman Zhang Kiu in search of Ming, where they find pallets of counterfeit purses. Ming gets the drop on Deeks, then escapes Nell as well. Sam and Callen capture her boss, Zhang, thought to be dead. Hetty points out to Granger that the Chinese government has to have sanctioned Zhang's trip to LA.
Eric discovers that the National Security agents were looking into Zhang, and that information was leaked to him. The team checks out two potential candidates for the leak, and Callen and Sam find out it's Donna Merritt, who has killed Ming. It turns out that Merritt is ripping off Zhang, stealing and selling black-market medicine. They go to Merritt's office looking for the contraband, only to walk in on her being taken by Zhang's thugs. As the team picks off the thugs, Merritt thinks she's escaped, but Callen and Sam are waiting for her.
Hetty relieves Deeks at the hospital so he can get some sleep, and tries to get some response from Kensi,,who squeezes Hetty's hand.