Callen, G. is the twenty-fourth episode and season finale episode of NCIS: Los Angeles Season 1.
OSP races against time to stop a brutal, murderous cabal from launching a deadly nuclear war in the Middle East while Callen discovers some answers concerning his mysterious past and true identity.
- Callen finds evidence suggesting that he has a sister named Amy.
- It's revealed that Trent Kort and Callen know each other, having worked together in the past.
- Callen later discovers that his "sister" is in fact a woman named Hannah Lawson and the real Amy had drowned in an accident when she was eleven years old.
- This is also the last episode of the entire NCIS: Los Angeles series to have Peter Cambor listed as one of the main cast members. In all future appearances, he would be credited as a Special Guest Star.
- It is interesting to point out that during Callen's visit to Amy's foster home, when he stares at the wall containing the photos of the children who have lived at this home, a lot of the photos are used two or three times.
- Charlie O'Donnell and Lily O'Donnell are the children of series regular Chris O'Donnell (G. Callen).
|G. Callen||Chris O'Donnell||An NCIS Special Agent in charge of the Office of Special Projects field team and who is partnered with fellow NCIS Special Agent Sam Hanna.|
|Kensi Blye||Daniela Ruah||An NCIS Special Agent with the Office of Special Projects.|
|Sam Hanna||LL Cool J||An NCIS Special Agent with the Office of Special Projects and who is partnered with NCIS Special Agent G. Callen.|
|Nate Getz||Peter Cambor||Psychologist with the Office of Special Projects.|
|Henrietta Lange||Linda Hunt||Operations Manager for the Office of Special Projects.|
|Eric Beale||Barrett Foa||Tech Operator for the Office of Special Projects.|
|Trent Kort||David Dayan Fisher||CIA agent.|
|Amy Taylor||Jacqueline McKenzie|
|Karim Akbari||Eli Danker|
|Jessica Haymes||Nancy Linehan Charles|
|Adoptive Mother||Sarah Batsheva Graham|