Marg Helgenberger Back on CSI: 5 Things to Know About Tonight's 300th Episode

Ted Danson, Jorja Fox and more talk about hitting the milestone

By Jenna Mullins Oct 23, 2013 5:46 PMTags
CSI, 300th EpisodeMichael Yarish/CBS

CSI is turning 300, and even though we hear the show has had some work done, we still think the crime-solving series looks better than ever.

CSI airs its 300th episode tonight, and while you take a moment to grasp that the CBS procedural has been on that long, we'll let you in on some scoop about tonight's case and reveal some things you need to know for the milestone offering:

1. Willows Is Back: Marg Helgenberger, who left the series in 2012 after 12 seasons, makes her triumphant return tonight for the 300th episode. Why does Willows return? Well…

2. Flashbacks Are Involved: The CSI team is investigating the murder of a reclusive former casino mogul, who just happens to be a suspect in a similar crime back in 2000. Catherine is then brought back to help solve the cold case. The episode will flashback 14 years to the original case and show Catherine, Nick (George Eads), Greg (Eric Szmanda), Sara (Jorja Fox) and Ecklie (Marc Vann) back in the day. The flashbacks will serve as a tribute to the evolution of the CSI team.

3. Viewers Can Get Involved: The episode will have the number 300 hidden 14 times throughout the scenes. Gotta count 'em all!

4. A 90210 Alum Is Guest Starring: Jason Priestley, aka Brandon Walsh from the original Beverly Hills, 90210, is guest starring as the reclusive casino mogul. One Tree Hill's Bethany Joy Lenz will also appear.

5. Get Ready for Chills: Castmember Jon Wellner says the last scene of the episode is can't-miss viewing. "I think the fans will love the nostalgia of it all. The way they did the last scene of the episode, just reading the script gave me chills."

The big 300th episode, titled "Frame by Frame", airs tonight on CBS at 10 p.m. Watch a sneak peek clip below!