"NCIS" veteran actor Muse Watson is returning to the show for Season 13 set to premiere later this fall.

CarterMatt reports Watson confirmed the news by posting a photo of his dressing room on social media under the caption, "Home at NCIS. Ok, dressing room trailer." The riddle of how show executives plan to ring back his dead Mike Franks character remains a mystery.

Given Franks' close relationship with series star Leroy Jethro Gibbs (Mark Harmon), who at the end of last season was fighting for his life after being shot at least twice by a boy he befriended and tried to help, speculation is Franks could be brought back in flashback scenes where he encourages his pal to fight for life and recovery.

There is also talk Watson could reemerge to "fill a similar role in the present," more specifically appearing in dream sequences to talk with Gibbs in either an alternate reality or some other sort of illusionary vision.

Filming on Season 13 has already commenced, though network execs, apparently leery of leaking too many details about the crucial Gibbs storyline, are keeping virtually all other aspects of production under close and guard wrap.

The 63-year-old recently signed to return to the show, but terms of the deal were not widely publicized and the length of the contract remains somewhat of a mystery.

Appearing on a recent episode of "The Late Show with James Corden," Harmon told the host the show "births characters leaving." Harmon added, "It's not my choice, number one, but I think anybody is replaceable."

The finale of Season 12 also found Tony (Michael Weatherly) and Joanna (Mimi Rogers) in Afghanistan in search of the terrorist group responsible for the killing of Agent Dorneget (Matt Jones).

Season 13 of "NCIS" is expected to be back on the CBS airwaves sometime in September.