Season Four Premiere. 'Boko Haram'- The terrorist group Boko Haram is responsible for thousands of deaths in Nigeria. Now, the government is determined to drive these militants from the country. But is the hunt for insurgents causing as much harm as it's preventing? Former Navy SEAL and new VICE correspondent Kaj Larsen travels to Nigeria to see what this cat-and-mouse game means for the people caught in the middle of the fight. 'Unnatural Selection' - For centuries, scientists have been working to change the genetic traits of plants and animals. Now, a new gene-editing method called CRISPR has made that process astonishingly simple--so simple that it could easily be used on humans. Isobel Yeung reports from Brazil, Scotland, China, and the United States on the technological advances that could reshape evolution as we know it.