Marg Helgenberger

Catherine Willows is back!

Marg Helgenberger will return to CSI for the procedural's 300th episode, TVLine reports. One of CSI's original stars, Helgenberger left the series halfway through the 12th season.

"We were just really excited to have Marg come back because, obviously, she's such an important part of the history of CSI," executive producer Don McGill said. "And she was super excited. It was kismet!"

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The landmark episode will center on a cold case that "takes our characters back to the beginning," McGill explained. "They have to investigate a murder with the same M.O. and the same suspect from 14 years ago."

Helgenberger's appearance will partially take place in a series of flashbacks. "We will flash back 14 years to seminal moments that show Catherine, Nick (George Eads), Sara (Jorja Fox), Greg (Eric Szmanda) and Ecklie (Marc Vann) as they were, [and how that] informed the evolution of the characters now. It's going to be a really fun episode, very emotional, that honors 14 years of CSI," McGill said.

Are you excited that Helgenberger will be back?

CSI's 14th season premieres Wednesday, Sept. 25 at 10/9c on CBS. 

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