Callen, Sam and Kensi Hanna in the January 26, 2010 episode of NCIS: Los Angeles. It's called "Missing." Who do you think IS missing?

Chris O'Donnell has been terrific so far as G. Callen on NCIS: Los Angeles. He's the undercover agent to end all undercover agents.

Sam Hanna in the January 26, 2010 episode of NCIS: Los Angeles. It's called "Missing."

Callen is the man. He's so bad ass he doesn't even have a first name!

Kensi tries to coax info out of an important prisoner right before he is mysteriously poisoned to death. It didn't work, but they got what they needed from him just the same.

G. Callen was pretty strongly attached to an old alias, it turned out. The reason for that? A woman.

LL Cool J in "Past Lives." He's our favorite NCIS: Los Angeles star!

Sam Hanna (LL Cool J) is the man. You do not mess with this NCIS: LA agent.

Sam and G in "Breach," the first NCIS: Los Angeles episode of 2010. And it was a good one, too.

G. Callen is an NCIS legend. He blends seamlessly into any situation.

Sam Hanna in "Breach," the January 5, 2010 episode of NCIS: Los Angeles. He and Callen have quite the case on their hands.

A stripper becomes a target in "Breach." But it wasn't who the criminals were really after.