Mark Harmon is signed to return as Agent Gibbs in Season 13 of "NCIS," which is set to premiere on Sept. 22.

As reported by TV Line, how that comes to play out remains somewhat of a mystery. In the Season 12 finale, Gibbs suffers two gunshot wounds fired by Luke Harris, while the team is in Iraq tracking a terrorist group known as The Calling that preys on young children.

No one knows how bad Gibbs' injuries may prove to be, and recently Harmon himself raised the stakes by telling "The Late Late Show With James Corden" host the series "births characters leaving."

Later, Harmon added, "It's not my choice, number one, but I think anybody is replaceable."

Show executive Gary Glasberg has assured fans the new season will kick off just as intensely as the previous one ended. Last season's final scenes also found Tony (Michael Weatherly) and Joanna (Mimi Rogers) roaming Afghanistan in search of the terror group responsible for the killing of Agent Dorneget (Matt Jones).

In Glasberg's mind, there's a method to all the madness. He later told the Hollywood Reporter all those scenes were intentionally filmed in such a "frenetic and chaotic manner" as a way of leaving the audience "unsettled and unsure of where we're headed."

No matter how the story lines actually play out, Glasberg assured fans they can expect more of what they've always seen from crew members.

"Regardless of the outcome, any time that Gibbs or one of our family members is in danger or injured, it significantly affects everyone," he said. "We'll have to see the long-term effects and the psychological effects, but they'll undoubtedly, as they always are, be there for each other."

Glasberg later explained he and the writing staff have developed some of the ongoing story lines as a way of raising the perplexing question of what happens when women and children, who are traditionally seen as the first to be protected, are "not to be trusted."