Blood Sugar

Horatio's team investigates an explosion at the Cavanaugh Sugar factory in which worker Eduardo Santana has been killed after being buried under tons of sugar. Delko believes the explosion was caused by a build up of sugar dust and it's soon discovered that ventilation ducts had been closed to save money. Plant manager Christie Cavanaugh - daughter of owner Roger - claims a worker had instructions to keep a door open, but he'd left his post to take sick worker Nina Costillo home. The door had closed with explosive results.

Just before the explosion, Santana had fallen or been pushed into a sugar hopper from a factory walkway where Walter discovers a horse hair, leading the team to supervisor Luis Avilla, who had used the horse that morning. Avilla admits he'd been instructing Santana but claims he was fine when he'd left him.

Horatio learns that Roger Cavanaugh had donated blood to Santana following a tractor accident, and it's soon revealed that Santana was Roger's son and that the factory owner had changed his will to leave half his estate to the young man. Then the CSIs discover that Christie had hired someone to hack into her father's computer and had found out about the will. Could Christie have caused Santana's death?

Nina Costillo tells Horatio that Roger allowed raids by the Immigration department to keep them off his back and had told them to deport Avilla's son instead of Santana. It seems an embittered Avilla had confronted Santana on the walkway and the young man had fallen into the hopper.

Confronted by Horatio, Avilla pulls a gun and takes Roger hostage. Though Horatio talks him into releasing his boss, Roger charges him and shots are exchanged. Avilla is wounded but Roger Cavanaugh lies dead.

Christie inherits the factory but is persuaded by Horatio to set up a scholarship fund, the first recipients of which are Nina Costillo and her sister, Isabel.