Four Kingdoms Duology Books in Order

Most of Melanie Cellier's fairy tale books are linked stand-alones. The Four Kingdoms Duology does something different. It takes one tale, East of the Sun and West of the Moon, and lets it stretch across two books. That gives the story more room for secrets, reversals, and parallel character arcs than a single retelling usually gets.

The first book, To Ride the Wind, splits its attention between Charlotte and Princess Gwendolyn. Charlotte is a commoner who is pushed into a marriage she never chose, and her new husband comes wrapped in mystery. Gwen, meanwhile, lives high in the mountains among people set apart from the rest of the world, and she slowly realizes that her mother's plans threaten far more than one marriage alliance. Their stories are separate at first, but the series is built on the way those lives begin to knot together.

Friendship is just as important here as romance.

That is one of the things that gives this duology its own flavor inside the larger Four Kingdoms world. Charlotte and Gwen are not simply moving toward their respective love stories. They are also learning how to trust each other, how to push back against manipulation, and how to survive in a kingdom shaped by fear, secrecy, and old damage. By the time To Steal the Sun begins, both women have more to lose and far harder choices to make.

The mountain setting matters a lot. It makes the duology feel a little more enclosed, wintry, and haunted than some of Cellier's other fairy tale books. There is still court intrigue and emotional warmth, but there is also a stronger sense of being trapped inside a place whose rules were written by someone dangerous. The castle east of the sun and west of the moon feels like a storybook location with real teeth.

If you want a Four Kingdoms story with more room to breathe, more emphasis on female friendship, and a single retelling allowed to unfold on a larger scale, this is where to go. It is still recognizably Cellier, but it has a more sweeping, two-part rhythm than the stand-alone volumes around it.