“Grace Period” first aired April 3, 2007.

The fourth season of NCIS has dealt very little with contemporary personal loss. Past loss has been covered in detail. The murder of Special Agent Leroy Jethro Gibbs’ (Mark Harmon) family surfaces with quiet regularity. The death of former NCIS Special Agent Mike Franks’ (Muse Watson) son was the topic of the previous episode, “Iceman”. We get a little closer with Mossad Agent-on-Loan Ziva David’s (Cote de Pablo) budding relationship with a poisoned and dying IAEA agent in “Dead Man Walking”. However, these episodes may only be considered a Wagnerian prelude to “Grace Period” where Gibbs’ team is face to face with their own fragile mortality.

The episode opens with an NCIS team from the Pentagon manning a weekend stakeout on a tip of possible terrorist activity. The team is made up of group leader NCIS Agent Paula Cassidy (Jessica Steen), NCIS Agent Rick Hall (Sasha Roiz), and NCIS Agent Jim Nelson (Jacory Gums). Cassidy receives a call from her ostensible Middle Eastern operative who wants to meet in an empty building. Cassidy dispatches Hall and Nelson into the building which promptly explodes… break to the introduction. Meanwhile, Gibbs and Army Lt. Col. Hollis Mann (Susanna Thompson) are taking batting practice with Gibbs playfully instructing Mann while Mann shines him on. Gibbs gets the call, going to headquarters not using his inside voice, dispatching his crew to investigate the bombing.

At the crime scene, a space rented by an Islamic nonprofit group, NCIS Medical Examiner Dr. Donald "Ducky" Mallard (David McCallum) observes what Gibbs states — that the explosion appears to have been the part of a suicide bomber, whose head the team cannot find. A distraught Cassidy helps at the scene, visibly shaken when seeing her dead colleagues. Gibbs takes her outside for a sit down, instructing Special Agent Tony DiNozzo (Michael Weatherly) to find the bomber’s missing head. Gibbs gives Cassidy the old heave-ho in the back of an ambulance. Cassidy holds herself responsible for the death of her team. Special Agent Tim McGee (Sean Murray) is dramatically affected by the agents’ deaths as he had attended school with one of them. Gibbs informs the crew that it was supposed to be his team taking care of that weekend, inferring that it could have been two of their team dead.

The discussion is interrupted by the arrival of two Middle Eastern men, greatly anxious at the damage at the scene. They are members of the Islamic nonprofit Coalition for Peace. The two men, Jamal Malik (Dominic Rains) and Abdul Wahid (Haaz Sleiman) are looking for their friend, Yahzeed Fahad, who is the president of their organization. Conveniently, Ziva locates the bomber’s head in the building’s rafters and drops it to the floor where it is identified by his partners. The two men are taken back to NCIS headquarters and questioned by Gibbs and Ziva together, where they try and convince Gibbs they are not criminals. They do convince Gibbs they are innocent while on the other side of the glass DiNozzo tells Cassidy Gibbs wants her to remain at headquarters.