Karl and the police force investigate the murder of a man founddead at the bottom of his staircase. During theirinvestigation, Karl's team discovers an item at the scene ofthe crime that may be linked to other murders. Karl warnsCassandra to stay out of the case, but her connection to itmakes her unable to stop.
A kidnapped teen leads the team to a Navy SEAL who survivedcaptivity by the Taliban but may have committed murder afterreturning home. Also, Jimmy finally shares his findings aboutthe mysterious death of Parker's mother with his boss.
The team investigates the murder of a Marine who had recentlybeen handpicked for a classified mission. Also, Wheeler'spersonal life is upended, Lala is thrown by unexpected newsfrom Vera, and Gibbs and Diane double-date with Randy and hiswife.
Dave':s ambitious home improvement plans take a turn,prompting Calvin to step in, while Malcolm seeks Gemma'shelp to overcome writer's block. Meanwhile, Tina'ssuggestion for Daphne sparks a parenting dilemma for Courtney.
Murdoch pursues a thief when a diamond tiara is stolen during aspecial Christmas event, while Margaret Brackenreid tries toconvince Anna Pavlova to perform in a charity Nutcrackerballet.
When a large-scale explosion rocks a Brooklyn apartmentcomplex, the team quickly locates the perpetrator anddiscovers he's acting on the orders of a convicted feloncurrently serving time. Meanwhile, Isobel must name hersuccessor before she moves into her new role.
Colette':s effort to redirect holiday plans takes anunexpected turn when it lands her trapped in a car. Meanwhile,a surprising new friendship stirs up jealousy among the team.
UHOP veers into terror when Watson and the fellows are takenhostage by a man with a bomb strapped to his chest who isdesperate to find a cure for his 9-year-old daughter'sillness.
Dr. Wolf helps a ballerina recover after a mystery illness:the team tries to save Sam's life and get him on thetransplant list; secrets are revealed at the hospital'sannual holiday gala that change the course of thedoctors' lives.