G. Callen's Best Moment In NCIS: Los Angeles Season 1
G. Callen is a presence in "NCIS: LA" from the get-go, becoming the Special Agent-In-Charge at the Office of Special Projects in the series' first proper episode following a two-part backdoor pilot in the mainline "NCIS" series. However, from that point until just before the Season 1 finale, the series predominately highlights Callen's military aptitude, providing little insight into his personal life outside of some cursory details.
That all changes in the Season 1 finale, titled "Callen, G." after the character at its center. In the episode's climax, which also serves as Callen's best moment in all of Season 1, he learns from a woman he tracks down and believes to be his sister Amy (Jacqueline McKenzie) that his real sister died, and she — real name Hannah Lawson — lived as Amy during much of their respective upbringings in foster care without his knowledge.
On one hand, this revelation deepens Callen as a character, granting viewers significant insight into his psyche for the first time. Furthermore, the moment marks the beginning of an investigation into Callen's past that continues in subsequent seasons, meaning that it serves an important role in the series' bigger picture as well.
"NCIS: LA" has remained on the air for 12 seasons and counting, during which time Callen has developed significantly since learning about his sister's death and her impersonator. Nevertheless, this major Season 1 moment continues to influence who the character is today.