When Nell sends Sam to meet an informant who plans to blow the whistle on a military secret, Hanna's life is in danger when the man tries to run him down and kill him. Also, Kensi and Deeks debate whether or not to buy their first house.

In order to get intel on a matter of national security, Kensi must come face-to-face with a sociopath who has been obsessed with her since she put him in jail years ago. Also, though Deeks is desperate to keep Kensi safe, he is forced to leave NCIS.