Smallville :

A group of thieves hijack a LuthorCorp van, and steal a shipment of refined green meteor rock. Clark inadvertently witnesses the robbery of the truck carrying and is stunned to realize that he can't stop the thieves and they are as strong as he is. It turns out that they are manufacturing and inhaling liquid Kryptonite, which leads to enhanced strength.

To keep Clark from telling the police, the thugs attack Jonathan and Martha, leaving Clark feeling powerless and desperate for a way to protect his parents.