TV Guide 5USA Friday

A nuclear power plant inspector suffers radiation poisoning, forcing the team to consider the possibility that a foreign power deliberately targeted him. As the others investigate, Ziva spends time with the ailing victim - and begins to realise she is developing feelings for him. Drama, guest starring Matthew Marsden, with Cote de Pablo

Jessica visits the zoo to research her latest novel, where a venomous snake kills an animal rights activist. Mystified as to how the black mamba could escape, the amateur sleuth tries to discover whether there was a human hand behind the incident. Angela Lansbury stars

While performing an autopsy for a class of military students, Ducky discovers the cadaver he is using is the body of a murder victim. In trying to identify the corpse, Gibbs and his team are set on the trail of a career criminal specialising in identity fraud. Meanwhile, Ziva has difficulty separating her personal feelings and professional judgment. Starring David McCallum and Mark Harmon

A Navy Seal is shot dead while threatening to throw himself from the top of a building. An al-Qaeda operative emerges as the main suspect, but DiNozzo thinks the killer may actually be found closer to home. Elsewhere, a rumour spreads that Abby may be about to leave NCIS for good. Michael Weatherly and Pauley Perrette star in the American drama

The unit is called to examine the mysterious death of a sailor serving on a research vessel engaged in a top-secret mission. The ship proves to have been abandoned by its crew, and Ducky discovers the victim died from a highly contagious virus - putting everyone presently on board at risk. Drama, starring David McCallum, Mark Harmon, Michael Weatherly and Lauren Holly

Briscoe and Green investigate the case of a woman found bludgeoned to death with a paving slab at a subway station. A petty thief leads them to a man with a history of mental problems, recently released from prison, who confesses to the crime and a previous murder. However, the victim's ex-husband wants to know why the suspect was walking the streets in the first place

Briscoe and Green investigate the murder of a violinist with the New York Symphony Orchestra and find the trail leads back to her Svengali-like conductor. However, they have a difficult job getting the case to trial, with a reluctant witness, a suspicious judge and a talented lawyer standing between them and a guilty verdict

A gang leader is stabbed to death in a prison scuffle, and Briscoe and Green uncover a number of suspects as it becomes clear the victim had numerous enemies on both sides of the law. The investigation results in a charge, but McCoy faces an uphill battle to convict the accused. Drama, starring Jerry Orbach and Jesse L Martin

Briscoe and Green investigate the case of a couple found dead in their apartment, following a trail of drugs and money to the wife of an army officer responsible for anti-narcotics operations in Colombia. Despite the woman's reluctance to co-operate with the police, McCoy convinces her she has no choice but to risk her life in a bid to catch the murderer. Charlotte d'Amboise guest stars

Briscoe and Green investigate the case of a Hispanic man found dead from a severe chest trauma after being involved in a staged car accident with two other illegal immigrants - and soon find evidence linking similar incidents with the same employer, chiropractor and insurance adjuster. Jerry Orbach and Jesse L Martin star

When a young woman accuses a celebrity plastic surgeon and his girlfriend of sexual assault, Benson and the team must determine if the woman was attacked or if it was a night of sex games gone wrong. Mariska Hargitay stars

A serial rapist strikes again after two decades of silence, and SVU operatives are determined to uncover the elusive criminal and bring justice to his many victims. Stone discovers that his father worked on the case before it went cold. Mariska Hargitay and Philip Winchester star