Ducky is attacked by somone who claims to have information about his deceased half-brother on NCIS. "Spinning Wheel" is the tenth episode of the show's 13th season.
The team investigates the death of a retired Navy Lietenant, forcing Ducky to reveal his membership in a secret society that looks into cold cases on NCIS. "16 Years" is the seventh episode of the show's 13th season.
The team must figure out if the person who murdered a petty officer is a serial killer or a copycat on NCIS. "Viral" is the sixth episode of the show's 13th season.
If the doctors on board that hospital ship can't save Gibbs, nothing on NCIS will ever be the same. Watch NCIS Season 13 Episode 1 scheduled to air Tuesday, September 22, 2015.