Keppler is forced to face his past when an old face turns up in Vegas asking him for a favour. Grissom returns from his sabbatical.
Grissom is sent a miniature crime scene in a cardboard box and attempts to solve a murder before it is committed.
Nick and Keppler investigate when a charred body is discovered with most of the internal organs removed.
The CSI team is divided like never before when Catherine reluctantly agrees to help Keppler deceive their colleagues in order to catch a murderer.