Inside: Secret America

Synthetic drugs are explored in the opener of this series investigating controversial issues in the United States. They travel to the South, where local law enforcement is trying to shut down manufacturers and distributors — a difficult task, because the chemicals used are constantly changing and the law cannot keep up. They go undercover with Marines in San Diego to local smoke shops to see how easy it is for someone to buy synthetic marijuana and bath salts.

Mariana Van Zeller and Darren Foster visit a gun enthusiast community in Arizona, a state with some of the most permissive gun laws in America. In dramatic hidden-camera footage, Van Zeller and a private investigator purchase an AK-47 assault rifle in a fast food parking lot within an hour of making contact with the seller.

Many people think sex trafficking only happens on foreign shores. But in America, sex slavery is thriving. Van Zeller and Foster set out to uncover the truth behind the salacious trade, focusing on the men who buy and sell women in order to work them on the streets.

The images are disturbing; animal cruelty and abuse at the hands of food industry workers and research technicians. Van Zeller and Foster first meet with covert animal activists who lead hidden camera exposés that have resulted in increased scrutiny of slaughterhouses, farms and research labs. While activists push for stricter enforcement of animal cruelty laws and increased criminal prosecutions against offenders, industry executives and lawmakers are mounting their own counterattack.