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Abigail Hernandez — who was 14 when she was kidnapped while walking home from school in New Hampshire in October 2013 — described Friday both her abduction and how she survived nine months of captivity inside a storage container.

Hernandez, now 19, said she immediately began to strategize when she was abducted by Nathaniel Kibby, now 39.

“I remember thinking to myself, ‘OK, I got to work with this guy,’” Hernandez told ABC News’ “20/20.”  “I said [to him], ‘I don’t judge you for this. If you let me go, I won’t tell anybody about this.’”

Her initial negotiation attempts failed and Hernandez was brought to a storage container — where she lived in fear for the next nine months and was abused daily.

Hernandez told the outlet that Kibby used psychological fear to keep her afraid of escaping and being rescued.

“He told me that he had tripped the door so that if for any reason it was busted open the room would catch on fire … so if someone kicked open the door that I would quickly go up in flames,” she said.

“He told me that he had tripped the door so that if for any reason it was busted open the room would catch on fire … so if someone kicked open the door that I would quickly go up in flames.”

— Abigail Hernandez

Hernandez also described how her captor, who told her to call him “Master,” forced her to wear a shock collar “like dogs wear” around her neck, as a “more humane” way of keeping her quiet.

“I remember he put it on me,” Hernandez said. “And he told me, ‘OK, try and scream.’ And ... I just slowly started to raise my voice. And then, it shocked me. So, he's like, ‘OK, now you know what it feels like.’”

Missing Teen NH

Nathaniel Kibby was sentenced to 45-90 years in prison. (Associated Press)

But Hernandez never gave up hope, and strategized to gain the trust of Kibby. She told the outlet that she went along with all his plans, never disagreeing with her captor. The strategy paid off, and she was trusted to help Kibby with his counterfeit money scheme.

“I remember I never said ‘amen’ in my mind. I never wanted to end my prayers because I didn't want God to leave me,” Hernandez said. “I just really wanted to live.”

“I remember I never said ‘amen’ in my mind. I never wanted to end my prayers because I didn't want God to leave me. I just really wanted to live.”

— Abigail Hernandez

Kibby suddenly let Hernandez go free in July 2014 after Lauren Munday, a woman he had gone out on a date with, said she told police about his counterfeit money operation, the Union Leader of Manchester, N.H., reported.

Fearing police would investigate his home, Kibby released Hernandez on the same North Conway, N.H., road where he abducted her. Hernandez then walked home. Kibby was arrested seven days later at his home.

Kibby pleaded guilty to seven felony counts, including kidnapping and sexual assault. He was sentenced to 45-90 years in prison.

Hernandez, who now lives in Maine, is a new mother, the Union Leader reported.

When "20/20" asked how she survived, Hernandez said: “Just don't lose hope … even when you feel like you've lost everything, hope is something that nobody can take away from you. And just keep that. And it'll keep you going.”