On Tuesday, five Americans detained for years in Iran stepped off a plane back onto US soil. They were released in the US-Iran prisoner swap that also saw five Iranians freed and the US agreeing to 6 billion dollars of Iranian oil money being unfrozen. Per the deal, Iran is supposed to spend the money only on humanitarian goods like food and medicine.Among the five freed Americans: Siamak Namazi. The longest-held US citizen in Iran, detained since 2015. When he stepped off that plane yesterday, his brother Babak was there to greet him.NPR's Mary Louise Kelly speaks with Babak Namazi on what the prisoner swap means for his family.Email us at considerthis@npr.org.