Gibbs fights for his life on a Navy hospital ship, while DiNozzo and Joanna go to Shanghai to take down the Calling.
When Gibbs asks the team to help DEA Agent Luis Mitchell with a case, DiNozzo makes a discovery about Gibbs' connection to the agent; Gibbs debuts a new look.
Hours after calling Gibbs about a possible case, a Marine is found dead in Quantico; McGee and Bishop pose as a married couple.
Vance returns to field duty -- with Gibbs as his partner -- when a murder investigation has a connection to a former NCIS agent incarcerated for stealing evidence.
During an investigation, Abby is trapped in a pharmaceutical lab when armed men enter the building and take hostages.
When a petty officer is murdered, the crime matches a local serial killer's method of operation; Delilah and McGee prepare to move in together.
A murder forces Ducky to disclose his participation in a secret society devoted to solving cold cases.
Insurgents in Sudan attack volunteer doctors -- including the man married to DiNozzo's ex-girlfriend, Jeanne Benoit.
A petty officer hoping to prove his innocence volunteers to be court martialed by NCIS if the team investigates his case; Jake and Bishop talk about their marital issues.
A sailor who lost two siblings -- Marines who were killed in the line of duty -- needs a bone marrow transplant; Bishop returns to Oklahoma for Thanksgiving.
Ducky is attacked by a man who claims to have information about his half-brother, who died decades earlier; Jake and Bishop talk about their future.
Abby's brother becomes the prime suspect when the passengers and crew of a private plane traveling from New Orleans are poisoned.
A seaman who was prepared to testify before a grand jury is murdered, which leads the team to discover the resurgence of an international human trafficking ring; a storm causes power outages all over the city.
An unusual investigation takes place when the body of a murdered deep-sea diver and his suspected co-workers must stay in a decompression chamber for four days.
Secretary of the Navy Sarah Porter's daughter is kidnapped; NCIS Special Agent Valerie Page, McGee's childhood friend, assists the team with advance tactics training.
Dr. Cyril Taft finds key evidence when he is assigned to surgical duty for a suspect.
Personal plans are interrupted when errors are found in what seemed to be a straight-forward, closed case; McGee and Delilah argue whether work should be discussed during dinner.
After an American couple is attacked in Iraq, Gibbs questions the lone survivor of a Special Ops group that was attacked months earlier in the same area.
When a Navy officer is murdered, the team must determine whether the man's wife or mistress is lying; a homeless woman believes Anthony DiNozzo Sr. is her father.
After Special Agent DiNozzo's identity is stolen, the perpetrators use his name to begin blackmailing senators.
NCIS teams up with the FBI and Homeland Security to pursue two escaped British prisoners, one of them a former spy, who have crossed international borders.
Gibbs suspects that a 14-year-old who stopped a home invasion is holding back information; Vance and Fornell head to London as part of the case involving the escaped British spy.
The FBI and M16 continue their international manhunt as the escaped British spy leaves one agent fighting for his life in the ICU.