Eric sent checks for $10,000 to everyone on the team. The squad is enlisted to help DEA Agent Talia del Campo find a whistleblower, Martin Henderson, who's missing after the DEA agent protecting him was beheaded. Henderson was scheduled to testify against gun manufacturers marketing to drug cartels. Deeks and Kensi debate how to spend their windfall. two thugss make the mistake of attacking Sam and Rountree and they bring Carlyle Huntington in for interrogation. Deeks and Kensi discover they're being watched as they check out an address connected to Henderson. After Huntington has disrespectful banter with Kilbride, the admiral strongarms a name out of him: Miguel Flores. Flores runs from Sam then Fatima knocks him into the water. Deeks finds a body wrapped in plastic above the ceiling in Flores' home. Flores is working with the cartel to protect his family that's still in Mexico. Del Campo and Rountree interview gun owners at a retirement home. The receptionist Loretta was involved in a plot to use residents' IDs to buy guns for the cartels. Deeks finds those guns waiting to be smuggled stored behind the walls of Flores' home. Kilbride gets under Huntington's skin. Then the lawyer supplied to Huntington stabs him in the neck with poison before he can talk. Sam gets through to Flores, who determines that the cartel has found where Henderson is hiding at a warehouse, which is already on fire. Sam charges into the burning building to rescue the badly wounded Henderson, who dies. Henderson recorded his testimony which officials refuse to use. Henderson sent out the same video testimony to hundreds of agents and officials.