"NCIS" is off for its 13th season this Tuesday. What can fans expect in the season premiere? It's going to be all about agent Leroy Jethro Gibbs and what happened to him after that shocking season-ender.

"NCIS" ended season 12 with a shocking fall for Gibbs (Mark Harmon) as he got shot by The Calling, a terrorist group. But fans need not worry, as showrunner, Gary Glasberg, confirmed that Gibbs will be back, though he may not be the same Gibbs whom fans came to know and love.

Glasberg says that the agent's road to recovery would not be an easy one and that it may have changed him into a different person — physically and emotionally. He continued to say that the first half of the new season will be an emotional rollercoaster ride, at least for Harmon's character.

This emotional rollercoaster means that Gibbs will try and draw strength from people from his past, even the dead ones. Hallucinatory scenes will bring back Mike Franks, his mentor and colleague killed in season eight. But it will not be all dead people, old characters from Gibbs' past will make some surprise appearances, assured Glasberg.

Because Gibbs will be recovering, his team will be stepping up and owning more and more responsibilities. One of those who will truly shine is Tony DiNozzzo (Michael Weatherly), who will assume leadership of the team. But Gibss won't be too happy about it.

Episode one and a few more episodes in the upcoming season will have "Two and a Half Men's" Jon Cryer making a guest appearance. He will play Dr. Cyril Taft, the doctor who will perform Gibbs' surgery and who will be bonded emotionally to him.

Follow Gibbs' journey to recovery in season 13 of "NCIS," which premieres on CBS this Sept. 22 at 8 p.m.