Tom Barnett

When an enraged gunman takes a hostage in a public square, the team must take drastic action and deal with the consequences.

When Rachel makes a promise to Sarah, it comes with a hefty price; Coady and Benchman scheme to track down the Castor Original.

Sarah, Felix and Mrs. S take a trip with the hopes of tracking down the Castor Original, however, they are not alone.

Paul finds the truth behind the Castor Boys' logbooks of names, pushing him into action; Felix is desperate for info on Sarah's whereabouts.

The CSIs must find who is trying to kill a young, sexy couple just released from jail. Leo and Sienna's illegal activities transformed them from common criminals to media darlings, but now their past is catching up with them. However, after they are released from jail, their past misdeeds catch up with them. Meanwhile, Calleigh's ex-boyfriend from the U.S. Treasury office is assigned to help her on the case.

Sam’s negotiating skills and feelings towards the SRU are tested when he bonds with an ex-soldier who’s booby-trapped an arena.