Worst Nightmare

A teenage girl is kidnapped from her middle school on the Quantico marine base, prompting NCIS to investigate. Nicholas Mason, the missing girl's grandfather, complicates matters when he arranges a ransom drop without informing NCIS. The team find a trail of dead bodies leading back to Mason, who admits he was a part of a black operations team that worked within the law, but outside the chain of command. Someone is using Mason's granddaughter to lure him out of retirement and lead them to the other team members. The kidnapper is the girl's high school English teacher, who was formerly a member of Mason's team and is seeking redemption for his past actions by killing off his team-mates. Meanwhile, three interns are assigned to NCIS; Abby is suspicious after her last assistant's attempt to kill her, Palmer feels ineffective after Ducky bonds with his intern, and McGee must contend with an intern who shows no interest in field work at all. Using an elaborate ploy, the team manages to trick the kidnapper into revealing where he was hiding the girl and arrest him. Meanwhile, the disobedient intern begins showing an interest in law enforcement and Gibbs later hands him an NCIS application form.