Spies. Terrorists. Arms dealers. For Special Agents "G" Callen (Chris O'Donnell), Sam Hanna (LL Cool J), and the rest of the Naval Criminal Investigative Service, it's just another day in paradise. But there's no time to lounge when the biggest cases of their careers come calling, whether it's local crises like the murder of a Naval lieutenant or the theft of a drone prototype, or international affairs like an impending missile attack in the Middle East. Meanwhile, the high stakes in the field follow the agents home, as Special Agent Kensi Blye (Daniela Ruah) and LAPD liaison Marty Deeks (Eric Christian Olsen) consider whether they could have kids, and tech geniuses Eric (Barrett Foa) and Nell (Renée Felice Smith) struggle to maintain their relationship as Eric goes undercover. Likewise, a black-ops agent from Hetty's (Linda Hunt) past returns to seek revenge.