When Marine dog tags are found in a national forest by a group of teens, the NCIS team is called in to investigate. While searching for the campsite of the Marine, the team finds out that there was another person, possibly a woman, with him. The investigation takes them to an even more higher discovery -- there could be a serial killer killing women in the national forest.

When a robotic vehicle named "Otto," a part of a high level project of the Department of Defense, causes a death of a Navy Lieutenant, and then later almost kills Abby, the NCIS team must find out who sabotaged the vehicle and murdered the Navy Lieutenant. Meanwhile, Ziva realizes that Tony keeps on visiting the hospital. What is he doing there?