Grissom and Willows return to help the CSI team solve a catastrophic case that paralyzes all of Las Vegas, on the special two-part series finale. Past and current series stars scheduled to appear include William Petersen, Marg Helgenberger, Ted Danson, Jorja Fox, Eric Szmanda, Robert David Hall, Paul Guilfoyle, Wallace Langham, David Berman, Elisabeth Harnois and Jon Wellner. Also, Melinda Clarke returns as Lady Heather. (Part 2 of 2)