The gang mourn the death of Kate; they recall her and deal with her death. Ari puts a round into Abby's lab, and the NCIS gets a new director, who shares a history with Gibbs. Ducky accepts an invitation to an unusual meeting. [Continued.]

Ducky meets Ari, Tony follows Ziva, Ari secretly betrays Israel and Mossad, Ziva passes cash and a fake passport to Ari, Gibbs and Jen seek Ari but miss him, Ari finds Gibbs, and Ziva finds them. The gang attend Kate's funeral in Indiana.

Ziva returns. A 140-year-old iron casket shows up at the Smithsonian Institution; it contains the body of a UA Marine staff sergeant, so Gibbs and company investigate. The team chases the clues, follow a map, and figure out the story.

Two wives of two deployed enlisted Marines disappear; the NCIS investigates. McGee recalls something, and that gives the team a start. The two wives went into business together online, but it goes out of control. The gang figure it out.

A 6-year-old boy sees who kidnaps his father, a Naval officer who works with a highly classified online-encryption system; the boy calls the NCIS, so Gibbs and the team investigate and eventually solve the crimes and recover the father.

Tony and Ziva go undercover and under the covers as assassins, a married couple, who recently died, but who apparently have a contract to execute at the Marine Corps birthday ball in Washington. The NCIS gang figure it out and work it out.

The amputated legs of a young woman turn up aboard the Marine Corps Base, Quantico, Virginia; Gibbs and company investigate. Forensic evidence implicates Tony because a pro has framed him. Abby works hard, and the gang find the bad guy.

When McGee shoots an unarmed undercover cop, the team work to clear his name.

Three supermodels take part in a reality show aboard the Marine Corps Base at Quantico; one of them disappears but shows up dead on a fence; the NCIS investigates. The victim's boyfriend shows up dead at a motel. The gang figure out all.

While investigating at a port, Tony and Ziva encounter unexpected criminal activity; they become trapped inside a shipping container. Gibbs and McGee, with the help of Ducky and Abby, find not only their teammates but also the bad guys.

A woman Naval officer becomes abducted, and she calls NCIS on her cellphone; Gibbs and the gang investigate. She's involved with both a movement of nuclear-fuel rods and an anti-pervert group. The team find her, and they solve the case.

Two Korean wives of Marine sergeants die in execution-style shootings; while the NCIS investigates, a third such wife disappears. The team find the wife, then identify the shooter and figure out the shooter and the changes in that person.

While busting three Navy enlisted men running an automotive chop shop, Gibbs, Tony, and Ziva find a severed head in a cooler in the trunk of one of the cars. The gang find the rest of the body, the story, the answers, and the bad actors.

An ambulance ignites and explodes after picking up the body said to be that of a Marine lance corporal who died due to a car wreck; Gibbs and company investigate, partly to determine the identity of the body. Gibbs and Jen close the case.

In the Shenandoah National Park a bear eats a part of the body of a murdered Navy petty officer; Gibbs and company investigate. A woman companion has disappeared; the gang deduce her identity. Ziva finds her, and Gibbs nails the killer.

The team must stop a student, holding six classmates hostage, from detonating a bomb.

A boy at play on a frozen pond sees the body of a man below the surface. Gibbs and company investigate; they find three more bodies. The first was a Marine; the others were gang members. The team figure it out; Gibbs provides a solution.

Tony and Ziva go to the home of a woman Navy lieutenant and cryptologist; they find her dead, apparently by suicide. Gibbs and the gang find evidence of murder instead; after pursuing the wrong clues, they lose a mole but catch the killer.

A couple enter a room at a Navy Lodge and find bloody human body parts; the Gibbs team investigate. Gibbs and Ducky agree that the scene was a setup. An imbalanced former boyfriend stalks Abby. The gang chase the clues and figure them out.

A suspect collapses and dies while in the custody of Ziva; she becomes a suspect rather than an investigator. The team investigate. Then the director disappears, and her driver dies. Ducky clears Ziva, and Gibbs and his gang rescue Jen.

Aboard a Turkish-flag ship an explosion occurs, killing one person and leaving Gibbs comatose with burns, abrasions, and a concussion; the team investigate. Eventually Ducky welcomes Gibbs back, but Gibbs does not remember him. [Continued.]

Gibbs regains consciousness, but he's lost his memory since 1991. He starts to remember a few things; Jen helps, then an old buddy, then Ziva. Gibbs gets back his memory and a solution, gives a severe warning, becomes ignored, then quits.

A bomb explodes as Ziva passes; a Syrian informant and two FBI agents die. The FBI seeks Ziva, who hides and calls Gibbs in Mexico. Gibbs and the NCIS gang band together to help.

A former petty officer and federal prisoner, convicted of murder and bank robbery, escapes and contacts Fornell, who, with Gibbs, caught him. Fornell contacts Gibbs, who contacts Jen, who temporarily reinstates Gibbs. The team solve it.

Gibbs returns to remain indefinitely. A bloody, screaming woman (a Navy lieutenant) disappears from the rear of her stolen SUV; Gibbs and company investigate. Abby and Ducky help. The gang find the victim, the bad guys, and their story.

A traffic stop, a car crash, a Russian man with a pistol and false ID, a dead Navy chief petty officer, and the bloody letters NCIS all combine to require the attention of Gibbs and company; Franks lends a hand. Together they wrap it up.

While showing a house, a real-estate agent discovers the body of a Marine sitting in the living room.

On Halloween the Gibbs team investigate a gunshot wound to a Marine and the kidnapping of his 7-year-old daughter. The kidnapper demands $100K, and the mother disappears. The gang find the mother, the bad guys, the girl, and the answers.

A Marine colonel dies in an explosion when he hits a golf ball at the Army Navy Country Club in Arlington; both the NCIS and the Army CID investigate. The joint team later find a fourth bomb, and Ziva disarms it, but they lose the bad guy.

At a hotel in Washington, a homeless hero Marine veteran falls to his death, and a maid finds the body of a 14-year-old girl. Gibbs and company investigate; Ducky, Abby, and McGee help, Lee goes undercover, and the team find the bad guys.

At 02:30 Tim's little sister, Sarah, shows up at his pad, saying that she thinks that she's killed someone. He investigates alone, until Gibbs and the team are called to investigate the murder of a petty office on Sarah's college campus.

While replacing a furnace at Quantico, workers find a smoked body in the chimney; Gibbs and company investigate. Fornell shows interest, saying that the victim was a serial killer. Abby enables Gibbs and Fornell to confront the real killer.

While testing a robotic driverless SUV, a woman Navy lieutenant becomes trapped inside it, and she dies of carbon-monoxide poisoning; Gibbs and company investigate. McGee suggests murder, Abby has trouble, and the gang find the bad guy.

A woman Marine first lieutenant, born in Kuwait, who has served in intelligence, returns from Iraq and turns up dead in a motel room in a small town; Gibbs and company investigate, with both help and resistance, and find three bad guys.

Responding to a call, Gibbs and company find the body of a Marine major in an underground utility vault beneath a street intersection. Abby finds the cause of the death, and Gibbs and the gang find Sharif, the bomber from the golf course.

An illicit arms dealer reveals a deal involving another dealer; McGee and Ziva tail a key player, who dies. Ducky impersonates the dead man and meets the Frog, whom Jen has long pursued; much good results, but the gang do not get the Frog.

A couple find the body of a Navy petty officer in an abandoned restaurant in Georgetown; the Metro PD calls and helps the NCIS; Gibbs and company investigate. Messages leave clues leading to an exclusive nightclub. The gang figure it out.

A Navy lieutenant, a member of an international nuclear-inspection agency, asks Gibbs to solve the officer's own murder because he knows that someone has exposed him to radiation poisoning.

A family crypt in a mausoleum explodes when unsealed; Gibbs and company investigate; Ducky says that parts of at least three skeletons occupied the vault. The team identify and check out a suspect, and Gibbs and Hollis get a major surprise.

Someone attacks a Marine corporal and leaves him to die, facedown in a snowbank in a park; Gibbs and company investigate. Mike Franks shows up and takes part; he and Gibbs sort it out and work it out. Tony and Jeanne encounter a problem.

An explosion kills two NCIS agents from another team; Gibbs and company investigate; feelings and emotions run high. Ducky and Abby find evidence suggesting opposite answers, but the gang resolve the problem, and they solve the case.

Gibbs and company investigate a crime scene; while doing so McGee recognizes that key details duplicate details in his second novel, still unfinished and in progress. The gang find two bodies; they eventually find the delusional bad guy.

Jen meets with an informant about the Frog, but someone kills the witness; Gibbs and company investigate. Jen obsesses about catching the Frog. Abby produces many answers; although the gang persist, they find a surprise but no Frog.

A blind photographer takes a picture; his assistant sees the body of a sailor in the background, and she calls the NCIS; Gibbs and company pursue. The gang find a second body, which leads to another crime, three solutions, and the bad guy.

While Jen attends a conference in Paris, Gibbs serves as the acting director. When a taxicab delivers a fare to the NCIS headquarters, the passenger, a Yemeni, is DoA; the gang investigate. Jen diverts to Moscow, and many answers emerge.

Jen returns from Paris; at home she finds a curious sight. All NCIS agents in Washington must take polygraph tests; Gibbs and the gang look into that. Tony and Jeanne deal with an injured pedestrian; Jeanne introduces Tony to her father.

Tony meets Jeanne's father; Tony excuses himself to move his Mustang, which explodes while the gang watch; Ducky says that the victim is not Tony. The Frog meets Jen, but she lets him leave; Gibbs and others pursue him but arrive too late.

The NCIS gang investigate the death of a sailor in a hit-and-run wreck, which turns into a shoot-and-scoot; Ducky finds nearby the body of a young woman who gave birth and died before the wreck. The team figure out the lies and the case.

A Captain is killed at home with a spear. His wife is having an affair with his Major, whose prints are found at the scene. Jethro's ex-wife, Stephanie, is seeing the Major too. Lt. Col. Mann, Jethro's girlfriend, leads the investigation.

While demonstrating an autopsy, Ducky announces murder; Gibbs and company investigate. The victim worked for the FBI, which tried to catch a person who erased old identities and created new ones. The NCIS and the FBI catch the bad guys.

A Navy lieutenant threatens to jump from an 11th-floor ledge in Washington; the Metro PD calls the NCIS; Gibbs and company respond and investigate; Gibbs talks the man out of jumping, then someone shoots him. With help the gang find a mole.

An officer dies aboard a Naval research vessel at sea; the Gibbs team investigates; they find the body but initially nobody else. Ducky announces the cause of death and a gloomy outlook. The gang figure it out and leave in a borrowed boat.

A special friend of Gibbs's daughter asks for help with a Marine sergeant, who has begun stalking her. Gibbs gives him the word, but soon someone abducts the friend and tortures and kills the Marine. Gibbs and Tony solve it and work it out.

While a Navy rear admiral rides in a taxi, two motorcyclists, using silenced pistols, execute both men; Gibbs and company investigate. Ducky says that the target was the driver, who was a political refugee from Burundi. The gang solve it.

While McGee gives his den of Youth Rangers a tour of the NCIS headquarters, one of his boys pops up in a missing-persons database; Gibbs and company investigate. The team find lies, deception, a fugitive, a new murder, and the real killer.

A to-be-decorated Marine, Corporal Damon Werth, becomes violent during his PTSD treatment. He has fistfights with NCIS agents. It is found that he is on steroids, and a Navy contractor is suspected of experiments on him.

A Marine lance corporal, of Arabic lineage and the Islamic faith, dies two blocks from a mosque in Washington, DC; Gibbs and company investigate. Ducky uses an alternate method; Abby finds a deadly neurotoxin. A tip helps; justice prevails.

Someone has stolen new top-secret radar gear; the NCIS gets a tip about its location. During a stakeout of the site, McGee watches while a man dies; the radar disappears again. The gang and the Metro PD figure it out and catch the bad guy.

While seeking to serve a warrant, the Gibbs gang find cocaine, cash, and the dead body of the subject person; a dog bites McGee, who shoots the dog. Abby goes to bat for the dog, who helps to solve the case. The team nab the bad person.

Fornell and his Hoovers arrive in the squad bay; he tells that the Gibbs team is under investigation for the murder of the Frog. However, the Gibbs gang investigates the FBI, and they put the pieces together and explain them to the suits.

A Marine captain dies in a mortar explosion in Baghdad; the SecNav sends the body to Ducky, who finds that a bullet, not shrapnel, caused the death. Tony and Jardine investigate on site; they and the rest of the team together figure it out.

Ziva, undercover, goes on a date with a suspected serial killer (a Marine); Tony finds the fifth victim; the suspect threatens Ziva, who resists and shoots him with his piece. Gibbs and the team investigate, solve, and find a second killer.

A man dies at a retrofitting site at a Navy facility; Gibbs and company investigate. Palmer sees a fleeing person, who takes a shot at him; a second body turns up.

In Los Angeles, Jenny, with Tony and Ziva as a protective detail, attends the funeral for a retired long-time special agent, who supposedly died of a heart attack; Jenny hears a name, sees a man, makes pictures, and summons Mike Franks from Mexico; she tells him that she's the next person to die. Jen and Franks visit the home of the dead man; there they meet his girlfriend, whom they send to Nevada, but who winds up dead in Santa Monica. Jen and Franks check out an insurance policy at a diner in a desert, and she refuses help from Tony and Ziva; Franks steps outside in the back, then four men enter the diner, and gunshots ring out; Tony and Ziva find a mess inside. [To be continued.]

In the aftermath of Jenny's death, Assistant Director Vance searches for Franks, who escaped the diner after killing the fourth gunman. Meanwhile, Tony and Ziva try to locate the one responsible, while dealing with the fallout of failing in their assignment to protect the Director. The trail points to a former hitman called Natasha, who Jenny failed to assassinate in Paris nine years previously while on an assignment that she and Gibbs were working on together. Since Gibbs killed Natasha's lover, Natasha has returned to the U.S. seeking revenge. Natasha, who never saw it coming, is killed by Franks, after Gibbs set a trap for her at Jenny's house. Gibbs burns down the house to cover up Jenny's death, making the public believe she died of smoke inhalation. In the fallout of Jenny's funeral, newly appointed Director Vance shreds a page from his personnel file in the Director's office and terminates Ziva's liaison status (sending her back to Israel), reassigns McGee to the cyber crime division, and sends Tony to the USS Ronald Reagan. Vance then gives Gibbs personnel files for his new team members.

An attack has killed one and left Vance with serious injuries; Gibbs takes charge by Vance's order. Eli reveals details about an operation 22 years old. Gibbs and the gang put the pieces together. The bad guy emerges, and justice prevails.

Someone shoots and kills the executive officer (XO) of a Naval vessel, a commander, in his own stateroom; Gibbs and company investigate. However, a shrink (a persistent and presumptuous one) arrives to conduct mandatory psychologic evaluations for all members of the gang, and she accompanies them aboard the ship. Ziva recognizes the spent brass as Russian. Word of the murder spreads fast, for seven international journalists are aboard as guests; one reporter makes a confession and reveals a potential powder keg. The team continue, and they eventually find the solution. Meanwhile, the shrink also continues, eliciting a number of flashbacks, mostly related to Kate Todd, a former member and special agent. Eventually Tony and Gibbs realize who the shrink is, then she submits her report to the director.

At a diner an unknown person with a drawn pistol approaches Gibbs, who deals with him; then Gibbs experiences flashbacks and fantasies, which Franks explains. The next day McGee announces a decision, then the gang gear up and head out.

Tis the season to be hacking. In a Christmas letter to his father, McGee describes in detail a case in which he, Gibbs and the rest of the NCIS team investigate the hackers who are responsible for the Internet going down in the D.C. area.

The NCIS cyber case turns into a united global effort after evidence confirms "The Calling," an international terrorist group that recruits children through the Internet, has been purchasing German S-mines off the black market.

In Los Angeles, Jenny, with Tony and Ziva as a protective detail, attends the funeral for a retired long-time special agent, who supposedly died of a heart attack; Jenny hears a name, sees a man, makes pictures, and summons Mike Franks from Mexico; she tells him that she's the next person to die. Jen and Franks visit the home of the dead man; there they meet his girlfriend, whom they send to Nevada, but who winds up dead in Santa Monica. Jen and Franks check out an insurance policy at a diner in a desert, and she refuses help from Tony and Ziva; Franks steps outside in the back, then four men enter the diner, and gunshots ring out; Tony and Ziva find a mess inside. [To be continued.]

Jen meets with an informant about the Frog, but someone kills the witness; Gibbs and company investigate. Jen obsesses about catching the Frog. Abby produces many answers; although the gang persist, they find a surprise but no Frog.

In the aftermath of Jenny's death, Assistant Director Vance searches for Franks, who escaped the diner after killing the fourth gunman. Meanwhile, Tony and Ziva try to locate the one responsible, while dealing with the fallout of failing in their assignment to protect the Director. The trail points to a former hitman called Natasha, who Jenny failed to assassinate in Paris nine years previously while on an assignment that she and Gibbs were working on together. Since Gibbs killed Natasha's lover, Natasha has returned to the U.S. seeking revenge. Natasha, who never saw it coming, is killed by Franks, after Gibbs set a trap for her at Jenny's house. Gibbs burns down the house to cover up Jenny's death, making the public believe she died of smoke inhalation. In the fallout of Jenny's funeral, newly appointed Director Vance shreds a page from his personnel file in the Director's office and terminates Ziva's liaison status (sending her back to Israel), reassigns McGee to the cyber crime division, and sends Tony to the USS Ronald Reagan. Vance then gives Gibbs personnel files for his new team members.

Fornell and his Hoovers arrive in the squad bay; he tells that the Gibbs team is under investigation for the murder of the Frog. However, the Gibbs gang investigates the FBI, and they put the pieces together and explain them to the suits.

A suspect collapses and dies while in the custody of Ziva; she becomes a suspect rather than an investigator. The team investigate. Then the director disappears, and her driver dies. Ducky clears Ziva, and Gibbs and his gang rescue Jen.

An illicit arms dealer reveals a deal involving another dealer; McGee and Ziva tail a key player, who dies. Ducky impersonates the dead man and meets the Frog, whom Jen has long pursued; much good results, but the gang do not get the Frog.

While Jen attends a conference in Paris, Gibbs serves as the acting director. When a taxicab delivers a fare to the NCIS headquarters, the passenger, a Yemeni, is DoA; the gang investigate. Jen diverts to Moscow, and many answers emerge.

An officer dies aboard a Naval research vessel at sea; the Gibbs team investigates; they find the body but initially nobody else. Ducky announces the cause of death and a gloomy outlook. The gang figure it out and leave in a borrowed boat.

Tony meets Jeanne's father; Tony excuses himself to move his Mustang, which explodes while the gang watch; Ducky says that the victim is not Tony. The Frog meets Jen, but she lets him leave; Gibbs and others pursue him but arrive too late.

Aboard a Turkish-flag ship an explosion occurs, killing one person and leaving Gibbs comatose with burns, abrasions, and a concussion; the team investigate. Eventually Ducky welcomes Gibbs back, but Gibbs does not remember him. [Continued.]