Gibbs and his team are called to the scene when a Marine's wife kills an intruder who tried to rape her.

Gibbs and his team discover that while Laura Rowen's (guest star Megan Ward) husband serves overseas, she leads a secret life. The NCIS team tracks a trail of her e-mails to a torrid website, which indicates she may have lured the attacker to her home under false pretenses. As the investigation progresses, the team discovers that they have a serial rapist and killer on the loose who uses websites to stalk his prey.