Assistant Director Owen Granger takes Kensi in 'protective custody' because she was the last person known to have contact with a secret elite snipers unit her late father belonged to. Granger doubts her loyalty, postulating she joined to be able to take revenge for his death on the unit, which recently lost several snipers. The boys are determined to find the real killer. They withhold evidence against her as long as possible and look into a CIA connection. A secret file is hoped to provide crucial clues.