Once every 48 years, bamboo forests in parts of northeast India go into exuberant flower. Then, like clockwork, the flowering is invariably followed by a plague of black rats that appear to spring from nowhere to spread destruction and famine in their wake. For the first time on film, NOVA and National Geographic capture this rat population explosion in vivid detail and show how scientists are unraveling the connections between bamboo flowering and rat outbreaks. Ultimately, their research should help local people better cope with the next attack—due in 2056.

What are dreams and why do we have them? Are they a window into a hidden realm within us? Science is only just beginning to understand. NOVA joins the leading dream researchers and witnesses the extraordinary experiments they use to investigate the world of sleep. From human narcoleptics to sleepwalking cats, from recurrent nightmares to those who can’t dream, each sequence contains a vital clue to the question these scientists are pursuing: Why do we dream?

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.

What will it mean when most of us can afford to have the information in our DNA—all three billion chemical letters of it—read, stored, and available for analysis? In "Cracking Your Genetic Code," NOVA reveals that we stand on the verge of a revolution. We meet cancer patients returned to robust health and a cystic fibrosis sufferer breathing easily because scientists have been able to pinpoint and neutralize the genetic abnormalities underlying their conditions. What are the moral dilemmas raised by the new technology? Will it help or hurt us to know our genetic destiny? What if such information falls into the hands of insurance companies, employers, and prospective mates? One thing is for certain: The new era of personalized, gene-based medicine is relevant to everyone. Soon, all of us may be deciding whether to join the ranks of the DNA generation.