NCIS: Los Angeles - Burned (1x23)

The #NCISLA team and Special Agent Sam Hanna (LL COOL J), race to find out who is behind a security breach that has blown Callen's cover and left the unit compromised.
Special Agent G. Callen (Chris O'Donnell) is forced to cut all ties from NCIS Los Angeles when his cover is blown.

source: CBS