'Lethal Dissent' Episode 2: An look at Iran's operations to find dissenters abroad

In the second episode of "Lethal Dissent," The World's investigative series with the podcast outfit On Spec, two close friends who work for the Iranian government follow their conscience. But, that puts them at odds with the regime. Now, one of them is dead. To figure out what might have happened, reporter Fariba Nawa goes back to the beginning.