The NCIS team uncovers a huge secret, as their mission to capture La Grenouille comes to an explosive and deadly conclusion.

During an autopsy, Ducky makes a startling discovery that turns a murder of a Petty Officer into a search for a missing infant. Meanwhile, Tony has to deal with his feelings for Jeanne.

Gibbs finds himself emotionally challenged when he agrees to investigate a crime connected to a friend of his daughter, who passed away years ago, and the investigation leads to a shocking conclusion.