Michael Weatherly
NCIS actor Michael Weatherly has been arrested for DUI. Here, he arrives at the 2014 People's Choice Awards in Los Angeles, California January 8, 2014. Reuters

"NCIS" Season 11, Episode 18, titled "Crescent City," airs Tuesday, Mar. 25 on CBS. This week's new episode is the first of a twin installment special, which serves as the backdoor pilot for "NCIS New Orleans." Mike Franks (Muse Watson) and Senior FBI Agent T.C. Fornell (Joe Spano) are listed as guest stars in the CBS episode promo.

Spoiler alert: This feature contains more spoilers on NCIS 11x18, aka Crescent City. Read at your own risk.

Showrunner Gary Glasberg revealed this spin-off special was raised by NCIS lead actor Mark Harmon. During a brainstorming session for NCIS Season 11 Episodes 18 and 19, Harmon told Glasberg to do the "sweeps two-parter" as a spin-off. This was revealed in this TVLine report.

CBS network executives have yet to officially order a full season of NCIS New Orleans. Muse Watson's Mike Franks appears in NCIS Season 11, Episode 18 possibly as a lucky charm. For solid luck, Joe Spano's FBI Agent Fornell is joining the new spin-off special.

Many fans agree that there is a special acting chemistry between Mark Harmon and Muse Watson. Throw in Joe Spano, and nothing could go wrong in NCIS 11 x 18. For NCIS fans who have been missing Ziva David (Cote de Pablo), this could be a welcome distraction.

Despite Franks' death, he remains an important part of Leroy Gibbs' life. Now in NCIS Season 11, Episode 18, viewers will meet another probie under Mike Franks. Welcome Gibbs' friend, Scott Bakula's Agent Dwayne Cassius Pride. Follow this link for more details on the NCIS New Orleans cast.

Everyone in the core cast of NCIS New Orleans will be in this week's new NCIS episode. Glasberg said Gibbs and Pride are "incredibly different." He added, "(T)here's an accessibility and a fun to [Pride] that Gibbs doesn't show."

The NCIS showrunner also spoke about the upcoming NCIS Season 11 finale. Glasberg has been quoted in previous reports saying the finale will focus on Tony DiNozzo (Michael Weatherly). But this time, he confirmed it will (also) be an "homage to Ralph Waite, to Jackson Gibbs."

WATCH: NCIS Season 11, Episode 18, aka 'Crescent City' (CBS Promo Video on YouTube)

NCIS Season 11 airs Tuesdays on CBS.

MORE NCIS TV Guide and Spoiler Features

'NCIS' Season 11 Spoilers, Speculations: Ziva David Return, Tony DiNozzo Focus, Jackson Gibbs Tribute, James Palmer Fatherhood [Video]
'NCIS' Season 11 Spoilers: Episode 15 Air Date, Hope for Ziva David and Tony DiNozzo Story in Finale? [Watch Promo Video]