The parents of American aid worker Kayla Mueller, captured by ISIS in 2013, have released a harrowing proof-of-life video featuring their daughter.

The 10-second clip from 2013 shows a terrified Mueller dressed in Islamic garb, facing the camera. “My name is Kayla Mueller. I need your help. I’ve been here too long and I’ve been very sick and it’s very terrifying here,” she says.

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The video was released by Mueller’s parents as part of an interview with ABC, which will air Friday. “You just go into almost a catatonic state, I think. You can’t even stand up,” the distraught father said.

Mueller was taken hostage in Aleppo, Syria, in August 2013 while serving as an aid worker. Because she was a white American, she was reportedly chosen by ISIS leader Abu Bakr al-Baghdadi’s as his personal sex slave.

ISIS claimed she was killed during a Jordanian airstrike on the terror group’s stronghold of Raqqa, Syria, in early 2015, but the Pentagon has disputed this account.