When a little girl wrote to CS Lewis asking him for an explanation of the Chronicles of Narnia, she never expected to get a reply.
But the letter Anne Jenkins from Hertfordshire received when she was just 10-years-old is to be displayed in Queen's University's new CS Lewis Reading Room.
Anne wrote to the Belfast born author in 1961 after being intrigued by a particular passage in The Silver Chair.
Recalling that time, Anne said she was fascinated by the books and the mystical world of Narnia.
"I just used to scrutinise them quite carefully and it was a little bit at the end of The Silver Chair, that I just didn't understand what he was saying," she said.
"It was where the dead king Caspian is brought back to life by Aslan the lion's blood and Eustace says 'hasn't he died' and the lion says 'yes he has died, most people have you know, even I have, there are very few people who haven't'.
"For some reason this stuck in my brain, so I asked my parents what does he mean by saying that most people have died?
"They didn't know, so they said that I should write and ask him."
There is a widely held view that CS Lewis' Narnian chronicles carry a predominantly Christian theme.
Anne has kept the envelope for 44 years
And as far as Anne is aware, her letter is the only known document from the author which supports the argument that Aslan represented Jesus Christ.
Anne said she has often thought about what exactly was in the author's mind at the time he wrote to her.
"I think it must have been the mood he was in at the time, his wife had died a couple of years before, maybe he was just thinking about it a lot at the time," she said.
"I see it as a coincidence, but maybe not."
In the letter Lewis simply states that the Lion, the Witch and the Wardrobe tells the story of the "Crucifixion of Christ and the resurrection".
He also explains that the story of Prince Caspian "tells the restoration of the true religion after the corruption".
"If you read the letter he wrote to other children, none of them are like this at all," Anne said.
Anne believes the letter is just too important a piece of historical literature not to be shared with the world.
CS Lewis wrote to Anne when she was just 10-years-old
"The letter could easily have got lost it is just lucky I have kept it safe all of these years, she said.
"The letter is so valuable and really needs to go into the public domain now rather than where I've kept it in a wardrobe, which is quite appropriate."
The letter will be displayed in Queen's University's new £44m library, which is due to open in 2009.
Until then it will be kept in the university library's special collection.