When an antiterrorism device is stolen, the team must quickly find the suspect and the device before an attack is made against Los Angeles. Meanwhile, Hetty realizes the case is bringing her back to someone from her past.

Callen and Sam enlist the help of a Gurkha, an elite Nepali soldier specializing in knife fighting, to retrieve a missing thumb drive. Meanwhile, Kensi and Deeks struggle to find a balance in their partnership.