It's official: CSI will end its 15-season run a two-hour finale on Sept. 27, CBS announced on Monday. Original cast members William Petersen and Marg Helgenberger will return for the show's send-off, and after the series finale, current star Ted Danson will join CSI: Cyber for its second season.

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Another show whose time might be running out is Person of Interest. The drama has been held until midseason - along with returning shows Two Broke Girls, Mike and Molly, The Odd Couple and Undercover Boss and newcomer Rush Hour - and its upcoming season will possibly be its last.

"We're having those conversations with the team right now," CBS Entertainment Chairpserson Nina Tassler said. "Jonathan Nolan and Greg Plageman came in and pitched really terrific ideas for the new season. And you know, we have to see. It's always been a very smart, creative show. We don't know yet whether or not it's going to be the end or not. If it is, we'll have a great ending."

For the first time since 1949, CBS will also stray from opening Monday nights with comedies. Although The Big Bang Theory and Life in Pieces will premiere on Mondays because of football, they will shift to Thursday in November. Supergirl will then take the 8/7c slot, where it will go head-to-head with Fox's Gotham. Tassler described the anticipated series, from Arrow and The Flash's Greg Berlanti, as "very true to the mythology," but revealed there will be some adjustments made. However, Kara Zor-El's cousin, aka Superman, will be referenced and a part of the show's universe.

CBS' adaptation of Limitless will debut on Tuesday nights and Bradley Cooper, who starred in the film on which the series is based, will appear in the pilot and recur subject to his availability.

As to CBS' late-night schedule, which is in the midst of a major overhaul with David Letterman and Craig Ferguson stepping down within months of each other, the network remains incredibly optimistic. "Obviously, it's a sad week for us as we say goodbye to Dave," Les Moonves said. However, he noted that Late Late Show host James Corden has been "way beyond my wildest dreams."

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Stephen Colbert will be taking over The Late Show in the fall and the former Comedy Central star is in the midst of developing his new late-night voice. "He's kind of in the bunker right now working on his format, working on all the details. But right now it will be a huge launch," Tassler said of Colbert's Late Show debut.

Check out CBS' fall schedule below:

MONDAY
8/7c: The Big Bang Theory/Life in Pieces (Supergirl takes this slot in November)
9/8c: Scorpion
10/9c: NCIS: Los Angeles

TUESDAY
8/7c: NCIS
9/8c: NCIS: New Orleans
10/9c: Limitless

WEDNESDAY
8/7c: Survivor
9/8c: Criminal Minds
10/9c: Code Black

THURSDAY
8/7c: NFL Thursday Night Football (The Big Bang Theory and Life in Pieces take these slots starting in November)
9/8c: Mom (starting in November)
9:30/8:30c: Angel from Hell (starting in November)
10/9c: Elementary (starting in November)

FRIDAY
8/7c: The Amazing Race
9/8c: Hawaii Five-0
10/9c: Blue Bloods

SATURDAY
8/7c: Crimetime Saturday
9/8c: Crimetime Saturday
10/9c: 48 Hours

SUNDAY
7/6c: 60 Minutes
8/7c: Madam Secretary
9/8c: The Good Wife
10/9c: CSI: Cyber

(Full Disclosure: TVGuide.com is owned by CBS.)