Thank you as I didn't know this. I guess I need to read the first book in the series. Should I read them in chronological or publication order? Perhaps I'll stick with publication order since I've already started that way.

I found this link: http://www.narniaweb.com/resources-links/in-what-order-shoul...

It reminds me of Haruhi Suzumiya https://en.wikipedia.org/wiki/Haruhi_Suzumiya (also excellent series)

The Magician's Nephew is definitely worth a read too.