Mustafah Abdulaziz for TIME Last year in the European Union, 104 people were arrested for helping refugees—more than in any other year on record—but Sara Mardini’s story may best illustrate just how fraught the issue has become. Mardini arrived on Greek shores in 2015 as a refugee from Syria, then returned as a humanitarian to help those who followed, rescuing migrants from boats and tending to their basic needs onshore. But in August 2018, Greek authorities arrested her and four colleagues on human-smuggling charges. They spent more than 100 days in jail before being released on bail. Now Mardini faces up to 25 years in prison if convicted. On Oct. 28, Amnesty International launched a campaign to pressure the Greek authorities to drop the case against her. “They think if you criminalize humanitarians and make volunteers disappear, refugees will stop coming,” Mardini tells TIME. “When I came by boat in 2015, I didn’t even know there were volunteers on the shoreline.” —Billy Perrigo