The official trailer of NCIS season 18 is finally here and it featured a lot of action-packed moments, especially for Mark Harmon's Leroy Jethro Gibbs. As previously confirmed, the premiere episode is going to address the storyline involving the Special Agent's mission in the past.

NCIS season 18 jumps back in time, wherein Gibbs returned from his "secret, personal mission" with a black eye. The premiere episode is all about the leader of a drug ring who sold drugs to the former FBI Agent Tobias Fornell's (Joe Spano) daughter, Emily (Juliette Angelo).

Based on the trailer, Gibbs and his old friend weren't on the same page in terms of tracking down the kingpin that supplied Emily counterfeited opioids that could've killed her. This storyline was introduced in the season 16 finale, "Daughters." That means the premiere episode is primarily set in 2019.

Gibbs wanted to do it the right way, but it looks like Fornell is fiery about it. This could be the reason why the former's got a black eye when he returned from this mission. Despite their potential disagreement and clash, they still have the common goal -- to catch the drug ring leader.

NCIS season 18 trailer shows other team members working on certain cases, as well. Dr. Jimmy Palmer (Brian Dietzen) found out that a cadaver is missing from the autopsy room, while Special Agent Nick Torres (Wilmer Valderrama) reported that a federal agent is in possible danger.

Also, Victoria Platt is set to appear as a guest star in the premiere. The actress will be playing the role of Special Agent Veronica "Ronnie" Tyler. As seen in the trailer, she is working alongside other agents and she is determined to find her missing daughter.

In the premiere photos of NCIS season 18, Gibbs can be seen in the laboratory with Palmer and Ronnie. It can be noted that he's got a black eye here, which suggests that this scene occurred in the past. Another image showed them discussing, with Palmer pressing an ice pack on his forehead.

It looks like these three were talking about some important matters, which is possibly connected to Gibb's secret mission. However, what's odd here is that this storyline wasn't immediately addressed when it was first introduced back in season 16.

Perhaps, there is a good reason why the series decided not to explore it instantly. There could be a huge revelation here, along with unexpected twists and turns. The good thing is that fans won't be waiting for too long in order to get answers as the show is coming back soon.

NCIS season 18 will be premiering on Tuesday, Nov. 17, on CBS.