She was played by Claudia Christian.
Louise Moreau was also a villainous mole for Chen; feeding intel to him for several months. Her calls to Chen habitually took place one our after the task force meetings, and she always spoke in Pashto in their conversations. Regarding the episode's events, the evil Moreau informed Chen about Clayton Reeves, who was planted inside Chen's plane by NCIS, and that led to Chen having the plane blown up. Reeves and pilot Paul Miller (the latter having been working with Chen) were both injured, with Miller committing suicide after his hospitalization.
Voice recognition performed by Abby Sciuto revealed Moreau as the villainess, and she was caught and shown the evidence by Gibbs and Vance. Moreau was later interrogated by Gibbs and Reeves, both of whom dismissed her motive, with the villainess admitting her role and stating that the meetings were actually beneficial to the plan; as they kept the task force tied up and gave Chen more time to perform. She was ordered to make a call to Edward Jintao, Chen's second-in-command, to set up a meeting so NCIS could catch him after he shot Qasim Naasir (who was later declared brain dead). Following their successful operation, Moreau was arrested (off-screen).