The United States has two of the longest unfortified borders in the world . . . and people arrive daily by air from outside the country, too. At those borders and airports are the border security officers who are on the front lines of making sure our nation is protected. They use their training, skill, and the latest technology to keep the bad guys out. Inside, learn how they keep our borders safe, every day, around the clock. Adventure, courage, talent . . . and service–they can all be found in the stories of brave men and women who go . . . ON A MISSION.