Almost 30 years ago, Ellen Sherman could never have imagined the impact one of her Miami high school students would come to have on her life.
"Brad Meltzer sat in the second row of my honors American history class when I was a teacher... and I remember him sitting there, because he was attentive, which not all high school juniors are," Sherman said.
Meltzer went on to become a best-selling thriller and mystery author, reports CBS News contributor Jamie Wax. He and Mrs. Sherman, as he still refers her to this day, barely kept in touch, but in 2013 Meltzer dedicated his book "History Decoded: The 10 Greatest Conspiracies of All Time" to his high school history teacher.
"I just wanted to thank my teacher. This woman changed my life; she gave me my love of history. She taught me things and had faith in me at a time when, really, very few teachers took a chance on me," Meltzer said.
When he reached out to Sherman to tell her the good news, she delivered some news of her own.
"Basically paraphrasing, she said, 'I need a kidney. I'm dying and I need a kidney. And could you -- we see you have so many people on Facebook, could you put it on Facebook for me?' When I read that email where she asked for help, my heart broke," Meltzer said.
Ellen Sherman was diagnosed with a disease 13 years ago that eventually led to kidney failure.
Brad posted the request to his 100,000 plus followers. The response was overwhelming.
"All these hundreds of people started calling the University of Miami," Sherman recounted. "We got a frantic call from the donor department: 'Please stop."'
Hundreds of people, strangers, were offering to get tested. But after a year and a half, Sherman still didn't have a match.
Time passed, and Meltzer reached out to his social media base once more.
"Then Amy came forward," Sherman said, laughing. "And then all my troubles were over."
Amy Waggoner was on Facebook earlier this year when she saw Meltzer's post. Usually loathing having to go to the doctor, she said something compelled her to get tested. A month later, she got the news that she was a match.
"It's beyond description, I think, because I've never once wavered. I've never once thought, 'Ugh, do I really want to do this?' It's never crossed my mind," Waggoner said. "I just knew that maybe in the back of my mind or something subconsciously told me that this was what I was meant to do. This is my purpose in life."
CBS News was there when all three of them met for the first time.
"Every once in a while, you see the best of us. And my teacher back then was the best of us," Meltzer said. "And now I get to see Amy step in who, come on, is the best of us. Someone who just says, 'There's a stranger out there that needs my help. I'll be there.' Tell me somethin' that's better than that. That to me is the definition of a hero."
As all of this was unfolding, Meltzer was writing his latest children's book "I am Helen Keller," which focuses on the importance of teachers.
"At the end of the book when you see who she really is, it says one last thing: Go say 'thank you' to that teacher who helped you when you needed it most. So, face to face, thank you, I love you for it. I appreciate it," Meltzer said to Sherman.
Through months of doctors appointments and procedures, Sherman's signature smile never left her face. And it was still there last week as she was wheeled into the 10-hour-long surgery at Jackson Memorial Hospital, just one more experience she would endure to save the life of a woman she had never met.
So could this be called a miracle?
"Miracles involve kind of Biblical passages to me. But, man, if you're going to put a miracle on the dictionary, I think you could put-- you know, a little, 'See Amy and Mrs. Sherman's story,'" Meltzer said.
"Amy's an inspiration to me. I open my eyes every day and think, what a miracle this is," Sherman said.
Both Waggoner and Sherman are out of the hospital and doing well. Sherman is already working to send all of the people who got tested, but weren't matches, to the Flood Sisters Kidney Foundation of America, which works to help people like Sherman who are in need of a kidney.