Alice Hines investigates how inaccurate drug tests could be determining hundreds of thousands of court cases and upending the lives of people around the country; Melissa Chan travels to Taiwan to find out how residents on the island are preparing against mounting threats of an invasion by China.

Hind Hassan travels to Syria to find out how a resurgent Islamic State nearly managed to free thousands of its imprisoned militants from under the nose of the Syrian Democratic Forces – one of America's closest allies in the fight against ISIS; Gianna Toboni meets young conservatives to see how their ideology is changing, and what it takes to become a right wing star in the U.S. today. Season finale.