'CSI' celebrates its 300th milestone episode with return of original cast member Marg Helgenberger

Her character will help solve a cold case that has haunted the team for 14 years

300^th episode will air on Wednesday, Oct. 23

"CSI: Crime Scene Investigation" will celebrate its 300th milestone episode with original cast member Marg Helgenberger returning as Catherine Willows to help solve a cold case that has haunted the team for 14 years, Wednesday, Oct. 23 (10 p.m.), on the CBS Television Network.

It's back to the beginning for "CSI's" 300th episode, when the team investigates a homicide in the home of a reclusive former casino mogul who was a suspect in a similar crime in 2000. The CSI team recalls who they were and where they were in order to solve the cold case.

The 14th season of "CSI: Crime Scene Investigation" premieres Wednesday, Sept. 25 (10 p.m.), on CBS. Ted Danson, Elisabeth Shue, George Eads, Paul Guilfoyle, Eric Szmanda, Robert David Hall, David Berman, Wallace Langham, Jorja Fox, Elisabeth Harnois and Jon Wellner star.

Helgenberger appeared for 12 seasons before her last episode aired Jan. 25, 2012.