Marg Helgenberger 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!"

See Robin Williams, Michael J. Fox and more familiar faces returning to fall TV