J.K. Rowling's Harry Potter series transported readers into a wizarding universe where anything is possible, and for that, a whole generation of children are endlessly grateful. One mom is especially thankful for the books because her daughter, who recently passed away from cancer, found comfort and solace in them during the family's darkest times.

"When I read her your stories, she didn't take to the clear distinction between good and evil, but instead loved the grey characters," mother Chrissy Hart wrote in a letter to Rowling. "You taught her that for every chemo she has to go through, there will be the opportunity to fly across a lake on a hippogriff. For every time her heart seizes with fear of pain, there will be me chasing it away with a patronus charm. Your words built a castle for her to move into when the prognosis got worse."

Actress Ellie Bamber read the touching note Saturday, March 12 at a Letter Lives performance, where celebrities read powerful and touching letters out loud. Star Wars's Daisy Ridley was so moved by the piece, she Instagrammed part of it.

"Mrs. Rowling, cancer threatened to take everything from my daughter, and your books turned out to be the fortress we so desperately needed to hide in," Hart continued.

You can read her full heartbreaking letter here. Maybe grab a box of tissues first.

H/T Cosmo.com