VIDEO: Sneak Peek - Tonight's 300th Episode of CSI: CRIME SCENE INVESTIGATION

On tonight's CSI: Crime Scene Investigation on CBS titled 'Frame by Frame,' Catherine Willows returns to help the CSIs solve a cold case that has haunted the team for 14 years, on the milestone 300th episode.

The episode airs tonight, Wednesday, Oct. 23 (10:00-11:00 PM, ET/PT) on the CBS Television Network. Marg Helgenberger returns as Catherine Willows. Jason Priestley guest stars as casino mogul Jack Witten.

CSI: Crime Scene Investigation is a fast-paced drama about a team of forensic investigators trained to solve crimes by examining the evidence. They are on the case 24/7, scouring the scene, collecting irrefutable evidence and finding the missing pieces that will solve the mystery. D.B. Russell, the CSI supervisor for the grave shift, is a family man and scientist, but not a nerd. Son of hippie parents, he's a left-coast Sherlock Holmes who devours crime novels and looks at every crime scene as if it were a story waiting to be told.