At a hotel in Cyprus an NCIS agent, Dan, dies, apparently of a cardiac arrest but actually of an injected drug used to produce that result; Eric learns that the suspected killer, using a Canadian passport, has just arrived at the LAX airport; Dan had investigated a rebel group in Chechnya, which he had suspected of buying small arms from a corrupt source within the US Navy. G and Sam tail the suspect, who rides a taxicab; the suspect rolls out, and the cabbie cuts out; Sam catches the man, and G loses the cabbie. The suspect, Jon, a British subject, provides some information through a deal; he's on his way to his next lethal action, in the LA area; G poses as Jon's backup; Sam, Kensi, and Deeks shadow G; then G and Sam learn the plan, and Kensi and Deeks check out the target, who speaks Chechen; Hetty gets outside help. Eric finds a clue, which allows the team to figure out the whole thing; the plan starts, then it changes, and the team wins anyway, but someone watches.
—DocRushing