The number of overdoses from fentanyl continues to soar, as do concerns from those in Washington. Immigration authorities say illicit fentanyl is flowing into the U.S. from Mexico through official ports of entry.Not everyone believes that's the full story.NPR's Joel Rose traveled to the border to find out what's really happening.Fentanyl is largely smuggled by U.S. citizens and other authorized border crossers. We hear the story of one of the smugglers. In participating regions, you'll also hear a local news segment to help you make sense of what's going on in your community.Email us at considerthis@npr.org.