The CSIs investigate the murder of Gwen Onetta, who was bludgeoned to death in the home of former casino mogul Jack Witten, a man who was accused of a similar murder almost a decade earlier. In the old case, Witten was accused of murdering Darcy Blaine, an 18 year-old drug addict whose body was never recovered, and Sara is convinced that he's killed again. Witten claims that he was asleep upstairs when Onetta was killed, but further doubt is cast on his alibi when Greg and Finlay discover another woman, Emily Bridwell, locked away in a secret upstairs preservation room. A few hours later, Emily dies in the hospital from silver poisoning, which was caused by the ingestion of an old role of 35mm film.The team links the camera that shot the footage of Darcy to Bob Greer, who used to work as a photographer for Witten, but they hit a dead end when they find Greer murdered in his own home. Hodges manages to restore the images from the film print, which show Darcy Blaine alive and well in Florida almost a year after she was supposedly murdered by Witten. Sara and the CSIs realize that Greer and Darcy framed Witten for murder to extort him years ago, and then tried to cover up their tracks when they learned that Witten had come into possession of the damning film footage.