When a mechanic is found murdered in a dark factory, the CSI team investigates whether the perpetrator was human or a humanoid robot with an AI operating system.

The CSI team investigates the death of a local antique shop owner who died from an apparent gunshot wound that is missing one important clue - the bullet. Also, Max makes an important breakthrough in the ongoing case with Ocho from the robotics factory.

After an explosion in a bio lab, the CSI team races to determine which nerve agent left one of their own unconscious, while the others explore a dangerous underground tunnel to find another CSI who got kidnapped during the blast.