Drug trafficking, poverty, gang violence, corruption and ethnic warfare have created some of the most dangerous hot spots on Earth. Witness follows our current generation of photojournalists into these conflict zones in Mexico, Libya, Brazil and South Sudan. In the four-part series, war photographers carry us into the heart of the human drama of the people in the action on the ground. We see what compels the photojournalist and experience why, when everyone else seeks cover, the photojournalist stands and moves closer.