Lisa says she first learned about her sister's capture in a devastating 2:30 a.m. phone call. "It was my brother-in-law—Laura's husband, Ian. The first words out of his mouth were, 'Laura was abducted by North Korean soldiers,'" she says. "At that moment, I just froze."

For the next four and a half months, Lisa spoke at support rallies to keep Laura and Euna in the headlines, all while hoping to send a message to the North Korean government. 

How Facebook helped Lisa Ling cope 

Throughout her sister's imprisonment, Lisa feared a documentary she filmed on North Korea would be used against Laura. "One of my first thoughts was, 'Oh my God, I hope they don't associate me with her.' Because I know that they were very displeased with what I had done there," Lisa says. "It was something that just continued to linger in my mind."

Still, Lisa's family remained optimistic. "We always maintained our hope," she says. "We're just so grateful that they were granted amnesty."