For every agent in the United States Secret Service, the most high-profile security assignment is to protect the president of the United States. In National Geographic's documentary series Chain of Command: The Secret Service viewers will be immersed in the high-stakes world of a law enforcement agency that very few people know much about. The second season of the Chain of Command franchise will premiere in early 2019 after National Geographic camera teams embed with the elite agency over the course of a year.