NCIS: Los Angeles season 12 premieres with a story featuring G. Callen (Chris O'Donnell) and Sam Hanna (LL Cool J) on an action-packed mission. The title of the first episode is "The Bear," which sees the two heading out to the desert.

Some premiere photos of NCIS: Los Angeles season 12 showed Callen and Sam on a seemingly dangerous mission. They'll be tracking down a Russian bomber, who goes missing after flying over the United States. However, the two will be facing a big problem along the way.

It is believed that other passengers on the plane try to destroy the evidence. Thus, Callen and Sam must secure the weapons and intel from the bomber before the Russians could destroy them. Some of the events within this episode could play out through most of the upcoming installment.

As for what else viewers can expect, NCIS: Los Angeles season 12 will also premiere with Hetty Lange (Linda Hunt) giving Nell Jones (Renee Felice Smith) a cryptic assignment. Other photos from the first episode teased Hunt's character preparing for her pivotal action scenes.

In one of the pictures, Hetty ditched her iconic sharp suits. Instead, she wears an army camouflage and a bulletproof vest. We'll possibly see the character in action, which is new since she often takes a backseat to the missions and acts as the team's Q.

Beyond the premiere, NCIS: Los Angeles season 12 brings a Christmas episode, as well. Fans were delighted by the news as the procedural drama doesn't usually feature such an episode, especially now, considering the current global health crisis.

Despite the challenges, the cast and crew found a way to make the episode happen. In fact, series star Daniela Ruah (Kesi Blye) shared a video on her Instagram account with co-star Eric Christian Olsen (Marty Deeks) -- teasing what's coming in the upcoming installment.

In the clip, the two seemed to enjoy the idea of filming the Christmas episode. For now, however, it remains unknown what the story would look like in the holiday special. Yet, it could feature some of them on a mission while others are celebrating the yuletide season.

For Deeks and Kensi, their relationship will continue to become a huge part of their storyline. They're planning to start a family, but they recognize that it's not easy. Both of them are dedicated to their jobs and a conflict between them could arise when their personal and professional lives are mixed up.

NCIS: Los Angeles season 12 is scheduled to premiere on Sunday, Nov. 8, on CBS.