The theme of this week’s Sound Effect is “Gatekeepers” — stories about people with power over who comes and goes. First, we hear what it’s like for a prison guard to be locked in with the inmates. Next, a story of escape and betrayal in one of the world’s most repressive countries. Then, the chilling words of a man ready to confront his fate — and his complicated journey to execution. Finally, we hear from a woman who once was tasked with helping determine who was approved to resettle from Vietnam to the U.S.