The Cases They Can't Forget Episode Rating Graph

A Navy contractor who wanted to sell secrets, two hackers who stole 220,000 U.S. military personal records and 17 sailors killed in a terrorist attack aboard the USS Cole. NCIS agents open up about their emotions, fears, frustrations and successes in solving investigations that have national and international impact - the cases they can't forget.

When a young Navy officer vanished without a trace along with $8600 from a supply ship during the Vietnam War, he was classified as a deserter and a thief. But his family believed something sinister happened.

When the investigation of a murdered Navy petty officer goes unsolved for nearly two decades, an NCIS agent goes undercover to turn up the heat on a suspect

A Marine's wife vanishes in California in 2014, and the search for her takes investigators into 115 degree temperatures in Joshua Tree National Park, and reveals a secret affair at a military base in Twentynine Palms, Cal.

A Navy lieutenant’s mysterious illness aboard the USS Forrestal leads to his death. Investigators say he was poisoned -- after 13 years, the trail leads to a suspect with an unusual motive for murder.

The disappearance of an Army nurse stationed at Fort Bragg is investigated.

The convicted killer of a young Florida mom speaks out for the first time and admits he didn't tell investigators everything -- but vows he didn't kill her. Is he telling the truth now?

In 1989, Annie Tahan disappeared without a trace. She left behind a newborn daughter and her boyfriend, Chief Petty Officer Michael Paalan, who told police that she had walked out on him. Four years after she disappeared, and with little to go on, authorities in Charleston, S.C. asked NCIS for help. "The mere fact that Michael Paalan was an active duty sailor at the time, we had an obligation to seek out the truth," said retired NCIS Special Agent Pete Hughes. Did Paalan have something to do with Tahan's disappearance? It would take years of challenging investigative work, multi-agency cooperation, surveillance and a sting operation to get answers. Moreover, they were investigating one of their own, making the case even tougher.

When a Marine was nearly killed in Kuwait, NCIS investigated a terror plot but instead found a love triangle.

Did a duplicitous online love affair between two people who never met lead to an innocent Marine being murdered?

Haunted by the death of a sailor's 10-year-old daughter in 1984, NCIS agents open up about the heartache and the three-decade long drive to find her killer.

In 1996, two Navy personnel were killed in a Virginia Beach apartment. The victims – Elise Makdessi and Quincy Brown – were coworkers at Oceana Naval Air Station. Makdessi’s husband, Eddie, said the couple had returned home from dinner and were accosted by Brown. Eddie Makdessi said Brown sexually assaulted and stabbed Elise. Eddie told police he was able to grab a gun and shoot Brown, but it was too late to save his wife. Because two sailors had been murdered, NCIS was called to the crime scene that very night. With not one, but two of their own now dead, the agents would not rest until the mystery at the heart of this case was solved. It would take 10 years as NCIS followed this twisting, turning tale that spanned two continents before coming to its stunning conclusion.