The CSI's are called out to investigate the disappearance of a boy whose father died four years ago. Soon a couple is arrested at a convenience store with a boy matching the description of the missing kid. The only problem is they both claim it is their son. Both parents have exactly the same picture of the boy, with a scar on exactly the same place on his face. They hope a DNA-test could confirm who the real parents are, but when this information comes to light, it lead to another bizarre twist, possibly murder.

When a seasoned sky diver is paralyzed after free falling to earth when his parachute doesn't deploy, he turns out to be linked to the strange death-by-airborne-toxins of two wealthy men with ties to Iran.

The team investigates two apparent corpses who aren't exactly dead at all.

When a teen opens fire in a police station, Russell is taken hostage.

Sara and Greg are quarantined after responding to a crime scene that’s contaminated with a deadly pathogen.