Estranged siblings Lindsay and Brad Morgan travel to Scotland at Christmas to visit their mother, who has a secret she's kept since their childhood.

The NCIS team investigates the disappearance of a Navy pilot who crashed her F-18, and discover her secret mission to find her ex-boyfriend's killer.

The team looks a bit deeper into the death of a Marine who was found at a UAV testing site, and they must determine if it was an accident or murder.

Magnum and Higgins find themselves stranded at sea and in increasingly desperate straits after being 'yacht-jacked'.

Magnum's fugitive ex, Hannah, approaches him for assistance in tracking down her missing CIA father.

Maggie and OA investigate a university's extreme political groups after a provocateur is killed following his speech in New York city.

An off duty police officer is killed in a violent armed robbery. Maggie and OA investigate the couple behind the spree od robberies.

The mystery surrounding a well-heeled murder victim gives Atwater and the team cause to suspect that the truth is more complex than it first appears.

An attempt to solve a shocking new crime leads Voight and the team to revisit a cold case, and there's a personal angle for Burgess and Ruzek.

The team come up against military red tape when they investigate a soldier suspected of sexual assault.

While searching for an abducted woman and her daughter, Benson and Alexandra Cabot cross paths.

The team races against time to solve a hit-and-run and stop a deadly arsonist wreaking havoc across the city.

NCIS goes into online dating to try solve the murder of a Navy captain who was found with an arrow through his heart. They must track down the killer.

When an investigative journalist is killed, the team unearth information linking the suspect to old cases. Maggie is reminded of her husband's death.

When a serial bomber starts targeting Wall Street elite, Maggie and OA investigate while Dana deals with a cocky profiler brought in to help.

With the team closing in on drug kingpin Javier Escano, the necessity of keeping his informant Anna in the dark causes more problems for Voight.

With things getting perilously close to breaking point, Voight and the team scramble to take down Escano once and for all before it's too late.

An indiscriminate sniper leaves the LA population terrified, but as 20 Squad tries to track the shooter down, they stumble across an unsolved murder.

Detective Charlie Hudson and Rex are an unstoppable team on a crime-solving journey, investigating puzzling crimes with their super senses.

The team are called in to investigate when a person suffering from Alzheimer's claims to have been assaulted.

Benson puts herself at risk as she attempts to take control of a hostage situation.