With Grissom away on sabbatical, the team are joined by a new CSI, Michael Keppler, who assists them on a case involving four unidentified women murdered over a span of 30 years.

Nick and Keppler investigate when a charred body is discovered with most of the internal organs removed, while the others probe the murder of a wealthy woman.

Keppler is forced to face his past when an old face turns up in Vegas asking him for a favour. Meanwhile, Grissom returns from his sabbatical, and wonders what's been going on in his absence.

The CSI team is divided when Catherine reluctantly agrees to help Keppler deceive their colleagues in order to catch a murderer. They create a fake murder scene and arrest a `fall guy', but Nick soon realises that something is amiss.

ET takes over an emergency room, Harry Potter winds up in a not-so-magical situation, and the reason the Avengers keep Hawkeye and Black Widow on the team is revealed.

Emily Roebling oversees construction of the Brooklyn Bridge, con-man Victor Lustig sells the Eiffel Tower, and Shakespeare steals the Globe Theatre.