NCIS: Los Angeles season 12 could further explore the story of Callen and Anna. A lot of things happened that led them to reunite and it's clear they do have feelings for each other. However, their current situations could also complicate their potential romance.

Callen and Anna's relationship may progress slower because of everything that's going on in their lives. The two might be facing more problems and could challenge both of them in NCIS: Los Angeles season 12. They could have conflicting decisions that could potentially impact their relationship.

Both of them have been through a lot and this could complicate things between them. While the two can save the day together, there's still a question of whether they could build a stable life together. They'll be facing normal problems like other couples if they decided to move forward and live together.

Still, it's nice to see Callen and Anna in a larger commitment, something that could lead to a wedding in the future. After all, they have their fair share of vulnerabilities. Callen, in particular, is struggling to let people eneter his life because of the things he's been through.

The two can help each other dealing with their emotions and conquering their demons. They both have their own issues, so they could lean on each other to get some strength and support. It's interesting to see how some of these will be explored in NCIS: Los Angeles season 12.

As for what else is coming for Callen, he and Sam might be dealing with the new adversary: Argento. This person could, particularly, challenge Callen on an emotional and intellectual level. He could bring more chaos because of the politics tied with him.

Callen and Sam could go undercover to learn more about Argento in NCIS: Los Angeles season 12. While there are only a few details about this person, he is considered a compelling villain and capable of causing more problems to the team.

Callen and Sam must do everything they can to stop Argento from whatever he's planning to do. But, their lives could be in danger since this new adversary is seemingly powerful. He is could potentially destroy whoever is on his way.

Meanwhile, filming of the series hasn't yet started due to the current health state of Los Angeles County. Cast and crew may not be able to go back working anytime soon until the situation gets a little bit better. Because of this, we could expect NCIS: Los Angeles season 12 arriving at a later date.