An explosion at an event alters Parsons' perspective on Gibbs and the team; DiNozzo and McGee investigate the case as civilians.
Determined to find Ziva, Tony follows leads in Israel; Gibbs and the team continue their search for Parsa and his expanding terrorist ring.
When a Navy lieutenant goes missing, the team uses Twitter to help solve the case; McGee's badge is missing.
A murder investigation brings Gibbs and McGee to Afghanistan where they encounter a women's shelter tied to Mike Franks' past.
DiNozzo remembers his time in the Baltimore Police Department when he chases a suspect from a 15-year-old case.
The Coast Guard Investigative Service works with the NCIS team when an explosion occurs on an oil rig; a mysterious prankster targets the team.
When family matters force Gibbs to leave mid-case, McGee and Tony argue over who should lead the murder investigation in his place.
The team is forced to take another look at a hit-and-run murder case; McGee becomes suspicious of Tony's unusual behavior.
An NSA analyst who predicted a security breach works with the team when the Secretary of Navy was bugged during a confidential briefing.
The team finds a link between the boyfriend of Gibbs' ex-wife and a murder victim; Ellie Bishop tries to adjust to being on the team.
When dozens of children from military families come down with a mysterious illness, the team tries to deliver a cure before the holidays.
The Department of Defense, including Gibbs' ex-girlfriend, helps the team search for a stolen drone linked to an elusive terrorist.
The team tracks down one of Parsa's cohorts by using evidence from the drone attack; McGee remains emotionally shaken.
A port authority officer's murder reveals a possible location for Parsa; Bishop reveals a past connection to the terrorist.
When faulty bulletproof vests are found in a truck full of stolen U.S.M.C. merchandise, the team must determine where they came from and track any defective vests that were shipped overseas.
Someone winds up dead when DiNozzo confronts a man impersonating a Navy officer; DiNozzo's father has a secret.
The team must identify the target when a bomb goes off in a dressing room at a military charity concert; Jimmy gets ready to be a father.
When a former NCIS agent's body washes ashore in New Orleans, Gibbs reunites with NCIS Special Agent Dwayne Cassius Pride (Scott Bakula) to determine if the murder was politically motivated or related to a well-known case.
Special Agent Pride (Scott Bakula) and Gibbs follow leads after evidence suggests the Privileged Killer has a copycat; DiNozzo receives a special souvenir from Bishop.
McGee's girlfriend, Delilah, turns to the team for help when she finds a break in a controversial case; McGee considers asking Delilah to move in.
When a Navy officer turns up dead on a rural road, the team must figure out if he was killed because he knew too much about an attack on a fellow officer; DiNozzo and McGee start a cleanse.
A Marine photographer goes missing before providing testimony in a highly publicized case; Abby helps a young homeless woman.
DiNozzo is sent to Paris to bring an Admiral's daughter home, but he needs help from the team after encountering a controversial crime scene.