A woman's body is discovered in a small press box at a high-school football field, apparently the victim of strangulation. The evidence leads investigators to two convicts, one of whom is still in prison. At the crime lab, an explosion destroys key evidence and leaves Greg and Sara injured.

The CSI team investigate a murder at a high stakes poker game.

Morgan, Sara and Fin try to relax at a forensics conference when a mass shooting occurs on site.

The CSI team investigates a murder with ties to two teenaged kidnapped girls.

The CSI unit faces the final showdown with the Gig Harbor killer whose motives are finally revealed. Meanwhile, Nick Stokes makes a decision that will affect the entire team moving forward.