S7, E9: Grissom and his team investigate a string of murders in Las Vegas that may be tied to an infamous mob boss from the 1970s who disappeared many years ago. After the mob boss's Cadillac mysteriously resurfaces in a Las Vegas lake and a photo turns up of the murder victims posing with him in the 1970s, the CSIs begin to investigate whether or not the notorious gangster, whose disappearance remains a mystery, might somehow be connected to the current killing spree in Las Vegas. (TV-PG)