A bomb goes off in the lobby of a Las Vegas office building, resulting in several casualties. Investigating, Grissom (William L. Petersen) and Catherine (Marg Helgenberger) zero in on a security guard with a working knowledge of explosives. After going to bed with the hooker he has befriended, Nick (George Eads) is the primary suspect when the woman turns up dead -- and Eckley (Marc Vann) has the unenviable task of determining Nick's innocence or guilt. ~ Hal Erickson, Rovi