In Part One of a Two-Part crossover episode to conclude on "Without A Trace," a kidnap victim from New York who went missing six years ago may be the same boy whose death Grissom and the CSI team are investigating in Las Vegas.

Hodges has ulterior motives when he stages hypothetical murders in the lab to give his colleagues a chance to play CSI. Also, everyone tries to reach out to Grissom after Sara's departure.