A reporter who spent years recording the lives of North Korean defectors in China maintained his journalistic objectivity even as he lived among those braving death to escape to freedom.

This demeanor – one defector told him he wouldn’t shed blood if pricked with a needle – contrasts starkly with the feelings the reporter shares in his memoir of the ordeal. Hark Joon Lee, whose book Crossing Heaven’s Border recounts the experience reporting on the refugees from 2007-2011, writes in his new book of his fears during the assignment, which he buried inside himself to the extent that he believes it caused his health to deteriorate. Years after the assignment ended, he writes of his outrage over the lack of attention defectors receive from the outside world.