(This program is no longer available for online streaming.) Over the millennia, thousands of creatures have developed that most sophisticated of biological and chemical weapons: venom. These complex chemicals can scramble your brain signals, paralyze your muscles, puncture your blood cells, even begin digesting you from within. But nature's most potent toxins might also contain the keys to a new generation of advanced drugs. Such drugs might help doctors treat heart attacks, cancer, diabetes, and other serious illnesses. Follow NOVA crews as they join scientists on a dangerous quest to track down and capture the world's most venomous animals—to find out both how they can kill us, and how they can save us.