I read this as the second novel in the series. It’s better than the first one (“The Magician’s Nephew”), but still pretty thin. There are no layers to the story of the plot – it’s very linear, very superficial. There are no twists.
It seems like a heavy allegory of the Christ story, but apparently Lewis maintains that was an accident.
I did like the denouement. I won’t ruin it, but after the climax, the story has a nice run-off.