With little evidence, the team turns to Scott to re-create the scene of the crime using his heightened senses of hearing and scent to track down the Petty Officer's killer. Meanwhile, Tony and Gibbs struggle with personal relationships.

As the NCIS Director returns from a controversial European junket, and Gibbs and his agents reluctantly prepare for hastily announced Homeland Security polygraph tests, tightly woven secrets among the team unravel, revealing the biggest surprise in this Season of Secrets. In addition, an unarmed Dinozzo and his girlfriend are held captive by a merciless drug-dealer.