They worked to save migrants’ lives. Now they’re on trial in Greece.

The trial of 24 volunteer aid workers begins on Tuesday on the Greek island of Lesbos. The aid workers stand accused of espionage and fraud, but the group says it was simply carrying out rescue operations in the Mediterranean, saving migrants who were trying to make it to Greek soil. Among the defendants is Syrian aid worker Sarah Mardini, the inspiration for a recent Netflix film called “The Swimmers.” Human rights groups say the charges are baseless and politically motivated. Host Marco Werman speaks with The World’s Europe correspondent Orla Barry.