If you asked a librarian what genre The Lion, the Witch, and the Wardrobe belonged to, they might say something like “juvenile fiction” or “high fantasy.” In truth, The Chronicles of Narnia belongs to many genres—including, in an odd sort of way, mystery. Although the Chronicles are a far cry from Arthur Conan Doyle’s works or G.K. Chesterton’s Father Brown Mysteries, they do present a few of their own mysteries, some of which C.S. Lewis never fully answered. One of these unanswered questions is precisely how time works in Narnia: how can the Pevensies leave England as children, grow up in Narnia, and yet, upon their return to England, be children once more?
A librarian who tells you the Chronicles are high fantasy would have a very good point. A defining element of fantasy is that it introduces fantastical things without explaining them. In this case, Lewis was not obligated to expound further than he did on theories of time, space, or travel between worlds.
When the Pevensies—Peter, Susan, Edmund, and Lucy—first entered Narnia, they entered as ordinary children. They aided Aslan and his army to defeat the White Witch and her century-long winter. The four were afterwards established as the Kings and Queens of Narnia. Throughout the story of The Lion, the Witch, and the Wardrobe, the Pevensies spent roughly fifteen years in the magical realm. As a side-effect of ruling a decade and a half in Narnia, they grew older. However, time in Narnia is different from ours. No matter how long or short of a period you spend there, events in our world will be the exact same as when you were whisked or called away.
Nevertheless, there are clues throughout the series that explain, in part, the Pevensies’ enigmatic double childhoods, such as this example in Prince Caspian:
“But, Peter,” said Lucy, “Look here, I know I can’t swim for nuts at home – in England, I mean. But couldn’t we all swim long ago – if it was long ago – when we were Kings and Queens in Narnia? We could ride then too, and do all sorts of things. Don’t you think –“
“Ah, but we were sort of grown-up then,” said Peter. “We reigned for years and years and learned to do things. Aren’t we back at our proper ages again now?
After unexpectedly crossing to our world through the Wardrobe for the second time, the Pevensies are now children again. Prince Caspian: The Return to Narnia recounts the events of the Second Battle of Beruna, along with many other things. Crossing a channel of water to reach Aslan’s How is much more of an ordeal to Lucy than it would have been for her or Edmund’s older-self a few hundred years ago. This time around is a new challenge for them all; Narnia has changed and so have they. Prior to the Pevensies’ first experience in Narnia, they behaved like normal schoolchildren; upon their return, they were once again ordinary kids except in their personalities.
In the end of the book, Peter and Susan were told that they would never be allowed back into Narnia. This is very similar to people growing up and suddenly the games they used to play in their head—their imaginations, really—disappear. Peter remained true to Narnia, even with the understanding that he would never return. Later, Susan gave up on Narnia. The things she used to think were real and fun left her. She remembered when they were real, but only as childish memories or “funny old games” she and her siblings used to play.
There are many mysteries to be found in the Chronicles of Narnia. Although C. S. Lewis was an astounding author, he was not known for extreme detail in his stories. On the other hand, as a reader, why have an imagination if you don’t use it?